Methods for minimizing shr in glass articles by producing a gas flow during pharmaceutical part converting

ABSTRACT

Systems for producing articles from glass tube include a converter having a base with a plurality of processing stations and a turret moveable relative to the base. The turret indexes a plurality of holders for holding the glass tubes successively through the processing stations. The systems further include a gas flow system or a suction system for producing a flow of gas through the glass tube during one or more heating, forming, separating or piercing operations. The flow of gas through the glass tube produced by the gas flow system or suction system may be sufficient to evacuate or purge volatile constituents of the glass from the glass tube and/or pierce a meniscus formed on the glass tube during separation, thereby reducing the Surface Hydrolytic Response (SHR) of the interior surface of the glass tube and articles made therefrom.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 120 ofU.S. Provisional Application No. 62/592,712 filed Nov. 30, 2017, andentitled “Methods for Minimizing SHR in Glass Articles By Producing aGas Flow During Pharmaceutical Part Converting,” the entire contents ofwhich are hereby incorporated by reference.

BACKGROUND Field

The present specification generally relates to systems and methods forproducing glass articles from glass tubes, in particular systems andmethods for reducing Surface Hydrolytic Response (SHR) of the glassarticle resulting from conversion of the glass tube.

Technical Background

Historically, glass has been used as the preferred material forpackaging pharmaceuticals because of its hermeticity, optical clarity,and excellent chemical durability relative to other materials.Specifically, the glass used in pharmaceutical packaging must haveadequate chemical durability so as to not affect the stability of thepharmaceutical formulations contained therein. Glasses having suitablechemical durability include those glass compositions within the ASTMstandard ‘Type IA’ and ‘Type IB’ glass compositions which have a provenhistory of chemical durability.

The chemical durability of a glass, as used herein, refers to theability of the glass to resist degradation upon exposure to specifiedchemical conditions. One measure of the chemical durability of the glassis the Surface Hydrolytic Response (SHR) of the glass, which can bethought of as a measure of the chemical stability of the glass whencontacted with a pharmaceutical composition. The SHR of the glass can beassessed according to one of three analytical tests described in UnitedStates Pharmacopiea (USP) <660> entitled “Containers-Glass 1”: the GlassGrains Test, the Surface Glass Test, and the Surface Etching Test. Othertests to assess the SHR of glass may include: DIN 12116 dated March 2001and entitled “Testing of glass—Resistance to attack by a boiling aqueoussolution of hydrochloric acid—Method of test and classification”; ISO695:1991 entitled “Glass—Resistance to attack by a boiling aqueoussolution of mixed alkali—Method of test and classification”; and ISO720:1985 entitled “Glass—Hydrolytic resistance of glass grains at 121degrees C.—Method of test and classification.” The chemical durabilityof the glass may also be assessed according to ISO 719:1985“Glass—Hydrolytic resistance of glass grains at 98 degrees C.—Method oftest and classification,” in addition to the above referenced standards.

Glass tubing may be converted into other glass articles, such as variousglass containers for use in pharmaceutical applications including,without limitation, vials, syringes, ampoules, cartridges and otherglass articles. The glass tubing may be converted, for example, in“converting machines.” Converting machines have been used for over 75years, and are currently made by various commercial and internalequipment suppliers. These converting machines typically reform longglass tube lengths into a plurality of glass articles using steps whichinclude flame working, rotating and stationary tool forming, thermalseparation, or score and shock cutoff steps.

During certain flame working operations that occur in the convertingmachine during the converting process, the glass tube may be heated totemperatures sufficient to vaporize one or more volatile constituents ofthe glass composition. Gas containing volatiles are injected into theworking tube's interior in piercing. Effects from exhaust systems,burners, buoyancy-driven chimney flow, and cooling jets can move thevolatile-containing gases in the tube interior, causing them to moveupward, downward or to stagnate. These vaporized chemical components cancondense on the cooler interior surfaces of the glass tube, which causean increase in the SHR of the glass article.

SUMMARY

Accordingly, a need exists for systems and methods for converting glasstubes into glass articles, such as pharmaceutical packaging, whilemaintaining the surface hydrolytic resistance of the glass articles.

In a first aspect of the present disclosure, a method for producing anarticle from a glass tube having an inner surface may includeintroducing the glass tube to a converter having a plurality ofprocessing stations comprising at least one heating station, at leastone forming station, and a separating station and heating a proximal endof the glass tube at the at least one heating station. Alkali isreleased from the glass tube during the heating. The method may furtherinclude forming at least one feature of the article at the proximal endof the glass tube in the at least one forming station, separating thearticle from the proximal end of the glass tube at the separatingstation, and producing a flow of gas adjacent to the proximal end of theglass tube. The flow of gas may be operable to remove at least a portionof the atmosphere in an interior of the glass tube.

A second aspect of the present disclosure may include the first aspect,wherein contamination of the inner surface by the alkali released fromthe glass tube may be at least reduced.

A third aspect of the present disclosure may include either of the firstor second aspects, wherein producing the flow of gas adjacent to theproximal end of the glass tube may comprise producing a flow of gas froma distal end towards the proximal end of the glass tube.

A fourth aspect of the present disclosure may include any of the firstthrough third aspects, wherein separating the article from the glasstube may comprise thermally separating the article from the glass tube,wherein a meniscus of glass may be formed on the proximal end of theglass tube during thermal separation and producing the flow of gasadjacent to the proximal end the glass tube may further comprise openingthe meniscus of glass.

A fifth aspect of the present disclosure may include any of the firstthrough fourth aspects, wherein producing the flow of gas adjacent tothe proximal end of the glass tube may comprise producing a positiveflow of gas orthogonal to a longitudinal axis of the glass tube adjacentto the proximal end of the glass tube.

A sixth aspect of the present disclosure may include any of the firstthrough fourth aspects, wherein producing the flow of gas adjacent tothe proximal end of the glass tube may comprise producing a positiveflow of gas external to the glass tube and at a non-zero angle with thelongitudinal axis of the glass tube.

A seventh aspect of the present disclosure may include any of the firstthrough sixth aspects, wherein producing the flow of gas adjacent to theproximal end of the glass tube may comprise introducing a gas pulse intothe distal end of the glass tube.

An eighth aspect of the present disclosure may include the seventhaspect, wherein separating the article from the glass tube may comprisethermally separating the article from the glass tube and forming ameniscus of glass across a proximal end of the glass tube, wherein thegas pulse may be sufficient to open the meniscus of the glass tube.

A ninth aspect of the present disclosure may include either of theseventh or eighth aspects, wherein the gas pulse may have a durationless than a sum of a dwell time and an index time of the converter.

A tenth aspect of the present disclosure may include any of the sevenththrough ninth aspects, further comprising controlling at least one of aduration of the gas pulse, a pressure of the gas pulse, or a volume flowrate of the gas pulse in response to changes in the tube diameter, wallthickness, glass type, converter operating temperatures, or combinationsof these.

An eleventh aspect of the present disclosure may include any of thefirst through fourth aspects, wherein producing the flow of gas adjacentto the proximal end of the glass tube may include producing a negativepressure at the proximal end of the glass tube.

A twelfth aspect of the present disclosure may include any of the firstthrough fourth aspects, wherein producing the flow of gas adjacent tothe proximal end of the glass tube comprises producing a negativepressure pulse adjacent to the proximal end of the glass tube.

A thirteenth aspect of the present disclosure may include the twelfthaspect, wherein separating the article from the glass tube may comprisethermally separating the article from the glass tube and forming ameniscus of glass across the proximal end of the glass tube, wherein thenegative pressure pulse may be sufficient to open the meniscus.

A fourteenth aspect of the present disclosure may include any of thefirst through fourth aspects, wherein producing the flow of gas adjacentto the proximal end of the glass tube may comprise producing the flow ofgas radially across a surface of a meniscus of glass formed on the glasstube during thermally separating the article from the glass tube,wherein the flow of gas may produce a negative pressure sufficient toopen the meniscus.

A fifteenth aspect of the present disclosure may include any of thefirst through fourteenth aspects, wherein the flow of gas adjacent tothe proximal end of the glass tube may be produced when the glass tubeis positioned in at least one of the plurality of processing stations.

A sixteenth aspect of the present disclosure may include any of thefirst through fourteenth aspects, further comprising indexing the glasstube between two of the plurality of processing stations, wherein theflow of gas adjacent to the proximal end of the glass tube may beproduced while indexing the glass tube between the two of the pluralityof processing stations.

In a seventeenth aspect of the present disclosure, a system forproducing glass articles from glass tubing may include a converterincluding a plurality of processing stations that include at least oneheating station, at least one forming station, and a separating station.The converter may be operable to index a glass tube through theplurality of processing stations. The system may further include a gasflow system operable to produce a flow of gas adjacent to a proximal endof the glass tube. Producing the flow of gas at the proximal end of theglass tube may be operable to remove at least a portion of an atmospherefrom the interior of the glass tube and reduce contamination of an innersurface of the glass tube by alkali released from the glass tube.

In an eighteenth aspect of the present disclosure, a system forproducing glass articles from glass tubing may include a converterincluding a plurality of processing stations that may include at leastone heating station, at least one forming station, and a separatingstation. The converter may be operable to index a glass tube through theplurality of processing stations. The system may further include a gasflow system operable to produce a negative pressure adjacent to aproximal end of the glass tube. The negative pressure may be operable toevacuate at least a portion of the atmosphere from the interior of theglass tube.

In a nineteenth aspects of the present disclosure, a system forproducing glass articles from glass tubing may include a converterincluding a plurality of processing stations that include at least oneheating station, at least one forming station, and a separating station.The converter may be operable to index a glass tube through theplurality of processing stations. The system may further include a gasflow system that includes a manifold fluidly couplable to a gas source,and a plurality of glass tube connectors, each glass tube connectorremovably coupleable to a distal end of the glass tube and fluidlycoupled to the manifold by a conduit. For at least one of the glass tubeconnectors, the gas flow system may be operable to pass a gas from themanifold, through the conduit, through the glass tube connector, andinto the distal end of the glass tube, and passing the gas into thedistal end of the glass tube may produce a flow of gas adjacent to aproximal end of the glass tube. The flow of gas may be operable toremove at least a portion of an atmosphere from an interior of the glasstube and reduce contamination of an inner surface of the glass tube byalkali released from the glass tube.

It is to be understood that both the foregoing general description andthe following detailed description describe various embodiments and areintended to provide an overview or framework for understanding thenature and character of the claimed subject matter. The accompanyingdrawings are included to provide a further understanding of the variousembodiments, and are incorporated into and constitute a part of thisspecification. The drawings illustrate the various embodiments describedherein, and together with the description serve to explain theprinciples and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts an embodiment of a converter for producingglass articles from glass tubes, according to one or more embodimentsshown and described herein;

FIG. 2 schematically depicts a top view of a main turret, secondaryturret, and feed turret of the converter of FIG. 1, according to one ormore embodiments shown and described herein;

FIG. 3A schematically depicts a heating station of the converter of FIG.1, according to one or more embodiments shown and described herein;

FIG. 3B schematically depicts a forming station of the converter of FIG.1, according to one or more embodiments shown and described herein;

FIG. 3C schematically depicts another embodiment of a forming station ofthe converter of FIG. 1, according to one or more embodiments shown anddescribed herein;

FIG. 3D schematically depicts a cooling station of the converter of FIG.1, according to one or more embodiments shown and described herein;

FIG. 3E schematically depicts a separating station of the converter ofFIG. 1, according to one or more embodiments shown and described herein;

FIG. 3F schematically depicts a piercing station of the converter ofFIG. 1, according to one or more embodiments shown and described herein;

FIG. 4 schematically depicts a perspective view of a glass tube prior toconversion in the converter of FIG. 1, according to one or moreembodiments shown and described herein;

FIG. 5 schematically depicts a gas flow system positioned at a piercingstation of the converter of FIG. 1, according to one or more embodimentsshown and described herein;

FIG. 6A schematically depicts another embodiment of a gas flow systemfor use with the converter of FIG. 1, according to one or moreembodiments shown and described herein;

FIG. 6B schematically depicts a side view of a cylindrical mount of thegas flow system of FIG. 6A, according to one or more embodiments shownand described herein;

FIG. 6C schematically depicts another embodiment of a cylindrical mountof the gas flow system of FIG. 6A, according to one or more embodimentsshown and described herein;

FIG. 7 schematically depicts another embodiment of a gas flow systemhaving an enclosure positioned at the piercing station of the converterof FIG. 1, according to one or more embodiments shown and describedherein;

FIG. 8 schematically depicts the gas flow system of FIG. 7 having anenclosure coupled to each holder of the main turret of the converter ofFIG. 1, according to one or more embodiments shown and described herein;

FIG. 9A schematically depicts a suction system positioned between twoprocessing stations of the converter of FIG. 1, according to one or moreembodiments shown and described herein;

FIG. 9B schematically depicts a top view of the suction system of FIG.9A, according to one or more embodiments shown and described herein;

FIG. 10 schematically depicts another embodiment of the suction systemof FIG. 9A positioned at a single processing station of the converter ofFIG. 1, according to one or more embodiments shown and described herein;

FIG. 11 schematically depicts yet another embodiment of the suctionsystem of FIG. 9A, according to one or more embodiments shown anddescribed herein;

FIG. 12A schematically depicts an embodiment of a piercing station ofthe converter of FIG. 1, according to one or more embodiments shown anddescribed herein;

FIG. 12B schematically depicts a piercing jet positioned in the piercingstation of FIG. 12A, according to one or more embodiments shown anddescribed herein;

FIG. 12C schematically depicts the piercing jet depicted in FIGS. 12Aand 12B incorporated into a separating station of the converter of FIG.1, according to one or more embodiments shown and described herein;

FIG. 13A schematically depicts another embodiment of a suction systemhaving a ring burner disposed at a processing station of the converterof FIG. 1, according to one or more embodiments shown and describedherein;

FIG. 13B schematically depicts a bottom view of the ring burner of thesuction system of FIG. 13A, according to one or more embodiments shownand described herein;

FIG. 13C schematically depicts a side view of the ring burner of thesuction system of FIG. 13A, according to one or more embodiments shownand described herein;

FIG. 14A schematically depicts yet another embodiment of a suctionsystem of the converter of FIG. 1 that includes an exhaust system,according to one or more embodiments shown and described herein;

FIG. 14B schematically depicts an alternative orientation of the inletvent of the exhaust system depicted in FIG. 14A, according to one ormore embodiments shown and described herein;

FIG. 15A schematically depicts another embodiment of a suction systemthat includes an exhaust system with an inlet vent positioned betweentwo processing stations of the converter of FIG. 1, according to one ormore embodiments shown and described herein;

FIG. 15B schematically depicts a top view of the suction system of FIG.15A, according to one or more embodiments shown and described herein;

FIG. 16A schematically depicts another embodiment of a gas flow systemof the converter of FIG. 1, according to one or more embodiments shownand described herein;

FIG. 16B schematically depicts further operation of the gas flow systemof FIG. 16A, according to one or more embodiments shown and describedherein;

FIG. 17 schematically depicts a glass tube connector of the gas flowsystem of FIG. 16A, according to one or more embodiments shown anddescribed herein;

FIG. 18 schematically depicts another embodiment of the gas flow systemof FIG. 16A, according to one or more embodiments shown and describedherein;

FIG. 19 schematically depicts an embodiment of a manifold of the gasflow system of FIG. 18, according to one or more embodiments shown anddescribed herein;

FIG. 20 schematically depicts another embodiment of a manifold of thegas flow system of FIG. 18, according to one or more embodiments shownand described herein;

FIG. 21A schematically depicts another embodiment of a suction system ofthe converter of FIG. 1, according to one or more embodiments shown anddescribed herein;

FIG. 21B schematically depicts operation of the suction system of FIG.21A, according to one or more embodiments shown and described herein;

FIG. 22 graphically depicts the SHR (y-axis) of glass vial samples madeon the converter of FIG. 1 having different configurations (x-axis)using a gas flow system illustrating influence of delivering gas flow atvarious points in the converting process, according to one or moreembodiments shown and described herein;

FIG. 23 graphically depicts the SHR (y-axis) of glass vials (x-axis)produced on the converter of FIG. 1 in which externally injected air wasadded at the piercing station and the meniscus of the glass tube wasopened with the same gas pulse, according to one or more embodimentsshown and described herein; and

FIG. 24 graphically depicts the SHR (y-axis) of glass vials produced bythe converter of FIG. 1 with and without suction induced downward flowinduced at burner stations after piercing, according to one or moreembodiments shown and described herein.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of systems andmethods for reducing the Surface Hydrolytic Response (SHR) of glassarticles produced from converting processes for converting glass tubeinto glass articles, examples of which are illustrated in theaccompanying drawings. Whenever possible, the same reference numeralswill be used throughout the drawings to refer to the same or like parts.Glass tubing may be converted into glass articles, in particular glassarticles for use in pharmaceutical applications, which may include,without limitation, vials, syringes, ampoules, cartridges and otherglass articles. The glass tubing may be converted into these glassarticles using a converter comprising a plurality of processingstations. The processing stations may include heating stations, formingstations, thermal separating stations, and piercing stations, amongother types of processing stations.

Certain processing stations, such as heating stations, separatingstations, and piercing stations, for example, may involve flame workingin which the glass is heated to temperatures in excess of the softeningand/or melt temperature of the glass, such as temperatures in excess of1500° C. These high temperatures to which the glass tube is heated maybe sufficient to vaporize one or more volatile constituents of theglass. The volatile constituents may vaporize within the interiorsurfaces and also may be transported into the internal volume of theglass tube during the conversion process. In a vial converting machinefor converting the glass tube into vials, a piercing station isrequired. In conventional vial converters, the piercing stationtypically requires a piercing burner to reopen the closed end (meniscus)of the working glass tube, the meniscus being formed in a precedingthermal separation step. With a typical piercing burner used inconventional vial converting machines, very high glass temperatures andexternal pressures are generated to open the glass meniscus. These hightemperatures release volatiles from the interior glass surfaces into theinterior of the tube. Further, when the meniscus opens, gases containinga concentration of volatiles are injected into the internal volume ofthe glass tube adding to the volatiles released prior to the meniscusopening. Throughout the converting process, there are a variety ofinteractions which induce pressure differences and hence induce flow ofthe gases within the internal volume of the glass tube, in either adownward or upward direction. For example, since the glass tube ishottest at its base, a buoyancy induced effect (chimney effect) tends topromote an upward flow of gases within the internal volume of the glasstube. Burners can create a Venturi effect, which can induce downward,upward, or neutral flow in the internal volume of the glass tube.Additionally, exhaust hood location, design, and operation can greatlyinfluence flow directions induced within the internal volume of theglass tube. Further, cooling gas jets may be deployed on convertingprocesses and can induce flow within the glass tube or sometimesentirely purge the internal volume of the working glass tube.

During the time the vaporized volatile constituents are present withinthe internal volume of the glass tube, the volatile constituents of thegases will condense on the interior surfaces of the glass tube, whichare generally cooler. Condensation of these volatile constituents of theglass onto the interior surface of the glass tube changes the surfacechemistry of the interior surface of the glass tube, which may adverselyimpact the SHR performance of the glass articles made from the glasstube. SHR is a measure of the chemical durability of the glass surfaceand is related to the solubility of glass components in various testsolutions. The objective of the low SHR requirement for pharmaceuticalpackaging is to maintain low solubility of glass components in thepharmaceutical compositions. According to USP <660>, glasses classifiedas Type I glasses have a high hydrolytic resistance making them suitablefor containing most parenteral and nonparenteral compositions. Depositsof volatile constituents on the interior surface of the glass articlescaused by condensation of vaporized volatile constituents may increasethe SHR of the glass article to levels unacceptable for Type Iclassification. Note that with borosilicate compositions, similarvolatilation/deposition physics also induce conditions generating glassdelamination, which is a considerable emerging concern withinborosilicate converted parts.

Conventional pharmaceutical part manufacturers are challenged to meetSHR performance requirements established by governmental bodies and SHRrecommendations from other non-governmental regulatory bodies. Variousstrategies have been developed to meet these SHR performancerequirements and recommendations; including imposing limitations onspeed and setup to minimize generation of volatiles; implementingexhaust system designs and setup to control internal flow directions;changing piercing burner designs and setup to minimize injection ofvolatile vapors during piercing; and/or passing the glass articles todownstream annealing processes or other post-converting treatments toremove or reincorporate the surface volatile deposits. However, theseapproaches to meeting SHR regulations substantially limit the processwindow of the converting process and can move the process in a directionunfavorable to glass strength and preventing defects, for example. Inparticular, these conventional approaches limit the production rateachievable by the given converting process, resulting in decreasedefficiency of the converter and decreased product quality of the glassarticles.

It is important to acknowledge that the volatile constituents and theirevolution rates from pharmaceutical glasses are strongly dependent onthe glass composition. Further, it is well understood that diffusionrates of volatile constituents from glasses follow an exponentialrelationship with temperature (typically Arrhenius equation). This meansthat the diffusion rate from the glass is strongly dependent on peaktemperature. The areas of highest temperature generate the highest rateof volatiles. This relationship of diffusion rate to temperature is asignificant driver for process sources of volatile generation. Forexample, boron and soda volatilize from Type 1B borosilicate glasses atrelatively rapid rates. Aluminosilicate glasses volalize mainlysoda—however the volatilation rate is much lower than Type 1B glasses atequivalent viscosity. The borosilicate diffusion curve is relativelyflat versus the steeper aluminosilicate diffusion curve, which meansthat for aluminosilicate glass, the points in the process in whichvolatile constituents are released from the glass generally include onlythe highest temperature areas in the converting process, such as thethermal separation step and the piercing step. Because the borosilicatediffusion curve is flatter, the borosilicate converting process exhibitsa higher generation rate of volatile constituents throughout theborosilicate converting process.

This application focuses on pharmaceutical processes for vialconversion. Vial convertors utilize a thermal separation step whichcreates the bottom of the vial. An undesired, but necessary, implicationis that the working end of the upper glass tube is concurrently closedby a meniscus of glass. In order to facilitate the formation of aflange, the meniscus is pierced and the end reopened. Modeling andmeasurements of this piercing process show very high temperatures up toand exceeding 1700° C. can be reached over short durations (˜0.1 sec).These high temperatures produce very high rates of diffusion of volatileconstituents from borosilicate glasses from the inside surfaces prior tomeniscus opening. Once the meniscus opening occurs inward, additionalvolatile laden gas is injected into the internal volume of the glasstube. Vial conversion, especially for larger vials, is well known in theindustry for being the most sensitive (versus cartridge and syringeconversion processes) in generating volatiles because of the hightemperatures required for piercing and injection at the piercing burner.Vials, especially large vials—where the hottest temperatures are needed,are the most challenged for SHR and delamination, in borosilicateglasses, for this reason. It should be noted that with larger glasstubes, the pressure to open the meniscus is less than the pressure toopen the meniscus on smaller glass tubes, so that the contributions ofvolatiles generated from the hot interior surface 146 of the glass tube102 prior to piercing predominate compared to the volatiles injectedinto the interior volume of the glass tube 102 with the piercing gasinjection.

It should be understood that these strategies demonstrated on a vialconvertor for SHR mitigation, however, can be applied to otherconverting processes, such as those for cartridges, syringes, ampoules,etc. Cartridge and syringe converting processes typically utilize scoreand break cutoff (versus thermal separation), so the high temperaturesand pierce volatile injection with vial separation and piercing are nota consideration. In those processes, however, it should be clear to oneskilled in the art that purging approaches in this disclosure can easilybe extended to occur after or during the highest volatilization(temperature) areas.

The present disclosure is directed to systems and methods for reducingand or preventing deposits of volatile constituents of the glass on theinterior surface of the glass tube. In particular, the systems andmethods disclosed herein produce a flow of gas adjacent to the proximalend of the glass tube. The flow of gas is operable to remove at least aportion of the atmosphere in an interior of the glass tube. For example,the flow of gas may be sufficient to counteract the chimney effect,which may reduce or prevent travel of the vaporized volatileconstituents upwards (i.e., in the +Z direction of the coordinate axisof the Figures) through the glass tube and condensation of the volatileconstituents on the interior surface of the glass tube. The flow of gasadjacent to the proximal end of the glass tube reduces contamination ofthe inner surface of the glass tube by alkali released from the glasstube during one or a plurality of converting operations. Reducingdeposits of volatile constituents of the glass on the interior surfacesof the glass tube may improve the SHR performance of the glass articlesmade from the glass tube.

Additionally, in some embodiments, the systems and methods may introducea gas pulse or a negative pressure pulse sufficient to open the meniscusformed on the proximal end of the glass tube during separation, whichmay enable elimination of the piercing burner from the converter.Elimination of the piercing burner may eliminate the greatest cause ofvolatilizing contstituents of the glass on the converter and may resultin improved SHR.

An embodiment of a system for producing articles from glass tube isdepicted in FIG. 5. In the embodiment depicted in FIG. 5, the system forproducing glass articles from glass tubing includes a converter 100having a plurality of processing stations that include at least oneheating station, at least one forming station, and a separating station.The converter 100 is operable to index a glass tube 102 through theplurality of processing stations. The system may also include a gas flowsystem 500 operable to produce a flow of gas adjacent to a proximal end152 of the glass tube 102. Producing the flow of gas at the proximal end152 of the glass tube 102 is operable to remove at least a portion of anatmosphere from the interior of the glass tube 102 and reducecontamination of an inner surface of the glass tube 102 by alkalireleased from the glass tube 102. Also included in this disclosure is amethod for producing an article from a glass tube 102 having an innersurface, the method including at least introducing the glass tube 102 tothe converter 100 having a plurality of processing stations that includeat least one heating station and at least one forming station, heatingthe proximal end 152 of the glass tube 102 at the at least one heatingstation, wherein alkali is released from the glass tube 102 during theheating, forming at least one feature of the article at the proximal end152 of the glass tube 102 in the at least one forming station,separating the article from the proximal end 152 of the glass tube 102at a separating station, and producing a flow of gas adjacent to theproximal end 152 of the glass tube 102. The flow of gas is operable toremove at least a portion of the atmosphere in an interior of the glasstube 102. The systems and methods disclosed herein may result in areduction in deposits of volatile constituents of the glass on theinterior surface of the glass tube 102, which may improve the SHRperformance of the glass articles made therefrom. The embodiment of FIG.5 as well as various other embodiments of the systems and methods forreducing SHR for the glass articles produced using the convertingprocesses will be described herein with specific reference to theappended drawings.

Directional terms as used herein—for example up, down, right, left,front, back, top, bottom—are made only with reference to the figures asdrawn and the coordinate axis provided therewith and are not intended toimply absolute orientation.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order, nor that specific orientations berequired with any apparatus. Accordingly, where a method claim does notactually recite an order to be followed by its steps, or that anyapparatus claim does not actually recite an order or orientation toindividual components, or it is not otherwise specifically stated in theclaims or description that the steps are to be limited to a specificorder, or that a specific order or orientation to components of anapparatus is not recited, it is in no way intended that an order ororientation be inferred, in any respect. This holds for any possiblenon-express basis for interpretation, including: matters of logic withrespect to arrangement of steps, operational flow, order of components,or orientation of components; plain meaning derived from grammaticalorganization or punctuation, and; the number or type of embodimentsdescribed in the specification.

As used herein, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to “a” component includes aspects having two or moresuch components, unless the context clearly indicates otherwise.

As used herein, the “proximal end” of the glass tube is the end of theglass tube oriented towards the processing stations of the converterrelative to the holder, and the “distal end” of the glass tube is theend of the glass tube oriented away from the processing station.

Referring now to FIG. 1, the converter 100 for producing glass articlesfrom a glass tube 102 is schematically depicted. The converter 100 maybe used to convert glass tubes 102 into a plurality of glass articles,such as, but not limited to, vials, syringes, cartridges, ampoules, orother glass articles. The converter 100 includes a base 104 having aplurality of processing stations 106, a main turret 108 positioned abovethe base 104 and rotatable relative to the base 104 about the centralaxis A, and a glass tube loading turret 110 positioned above the mainturret 108 for feeding glass tube 102 to the main turret 108. Theconverter 100 may also include a plurality of secondary processingstations 112 on the base 104 and a secondary turret 114, which isrotatable relative to the base 104.

As schematically depicted in FIG. 1, the base 104 of the converter 100is stationary and the processing stations 106 may be coupled to an upperportion 105 of the base 104. The plurality of processing stations 106are spaced apart from one another and arranged in a main circuit 116. Inone or more embodiments, the main circuit 116 may be circular so thatthe main turret 108 may index a glass tube 102 through the plurality ofprocessing stations 106 by rotation of the main turret 108 about thecentral axis A. Alternatively, in other embodiments, the main circuit116 may be linear. Although described herein in reference to acircular-shaped layout of processing stations 106, it is understood thatthe subject matter disclosed herein may apply equally well to convertershaving other arrangements of the processing stations 106.

The type and/or shape of the article to be made from the glass tube 102may influence the number of processing stations 106 coupled to the base104. The number of processing stations 106 of the main turret 108 may befrom 14 to 32 processing stations 106. Although the converter 100 andconverting process are described herein in the context of a converter100 having sixteen processing stations 106 in the main circuit 116, itis understood that the converter 100 may have more or less than sixteenprocessing stations 106 in the main circuit 116. The processing stations106 may include, by way of example and without limitation, one or moreheating, forming, polishing, cooling, separating, piercing, measuring,feeding, or discharge stations or other processing stations forproducing the glass articles from the glass tubes 102. The type and/orshape of the article to be made from the glass tube 102 may alsoinfluence the type of processing stations 106 and/or order of processingstations 106 of the converter 100.

The main turret 108 may be positioned above the base 104 and may berotatably coupled to the base 104 so that the main turret 108 isrotatable about the central axis A relative to the base 104. A drivemotor (not shown) may be utilized to rotate the main turret 108 relativeto the base 104. The main turret 108 includes a plurality of holders130, which are configured to removably secure each glass tube 102 to themain turret 108. The holders 130 may be clamps, chucks, or other holdingdevices, or combinations of holding devices. The holders 130 may orienteach glass tube 102 so that the glass tube 102 is generally parallel tothe central axis A of the main turret 108 and generally perpendicular tothe upper portion 105 of the base 104. Although the converter 100 isdescribed in this specification in the context of a vertically orientedconverter 100, it should be understood that the converter 100 may beoriented horizontally or at an angle. Each of the holders 130 extendsfrom a bottom portion 109 of the main turret 108 in a direction towardsthe base 104 (i.e., in the −Z direction relative to the coordinate axisin FIG. 1), and each holder 130 is oriented to position the glass tube102 in or proximate to each of the successive processing stations 106 ofthe main circuit 116 of the base 104 as the main turret 108 is indexedabout the central axis A. Vertical orientation of the glass tubes 102allows a downward protruding portion of each glass tube 102 to be cycledprogressively through the processing stations 106 of the main circuit116. In some embodiments, the converter 100 may be operable to indexeach of the plurality of holders 130 progressively through the pluralityof processing stations 106. Alternatively, in other embodiments, theconverter 100 may be operable to translate the plurality of holders 130continuously through the converting process. Each holder 130 may beindividually rotatable relative to the main turret 108 about holder axisD, which may be generally parallel to the central axis A of the mainturret 108. Each of the holders 130 may be operatively coupled to amotor (not shown), continuous drive belt, or other drive mechanism forrotation of each of the holders 130 relative to the main turret 108.Rotation of the holders 130 allows for rotation of the glass tube 102relative to stationary burners, forming tools, cooling nozzles, or otherfeatures of the processing stations 106.

Referring to FIGS. 1 and 2, the converter 100 may have a plurality ofsecondary processing stations 112, which are also spaced apart andarranged in a secondary circuit 118 (FIG. 2), and a secondary turret 114(FIG. 1) for indexing an article 103 (FIG. 1), which has been separatedfrom the glass tube 102, through the plurality of secondary processingstations 112. The secondary turret 114 may be rotatable about a secondaxis B relative to the base 104. The second axis B may be generallyparallel to central axis A of the main turret 108. The secondary turret114 also includes a plurality of holders 130 to hold the glass articles103 and position the glass articles 103 to engage with each of thesecondary processing stations 112 in succession. The secondary turret114 may receive the articles 103 from a separating station 206 (FIG. 2)of the main turret 108, index the articles 103 through the plurality ofsecondary processing stations 112 through rotation of the secondaryturret 114, and discharge the finished articles from the converter 100.

The glass tube loading turret 110 may be positioned above the mainturret 108. In embodiments, the glass tube loading turret 110 may beoffset from the central axis A of the main turret 108. The glass tubeloading turret 110 may be rotatable about an axis C, which may begenerally parallel to the central axis A of the main turret 108. Theglass tube loading turret 110 may be independently supported in astationary position relative to the main turret 108, and rotation of theglass tube loading turret 110 may be independent of the rotation of themain turret 108. Referring to FIGS. 1 and 2, in some embodiments, theglass tube loading turret 110 may include a plurality of loadingchannels 132 arranged in a circular circuit 134 and configured to holdglass tubes 102. The glass tube loading turret 110 may be positioned toorient one of the loading channels 132 into vertical alignment (i.e.,aligned in a direction parallel to the central axis A of the main turret108 and/or parallel to the Z axis of FIG. 1) with a processing station106 of the main circuit 116 of the converter 100 and the correspondingholders 130 on the main turret 108 that are indexed through theprocessing station 106 of the main circuit 116. In one or moreembodiments, the processing station 106 aligned with the glass tubeloading turret 110 may be a tube loading station 214 (FIG. 2). When theconverter 100 has converted all or at least a portion of the glass tube102 at a specific holder position 136 into one or more articles, theglass tube loading turret 110 may deliver a new length of glass tube 102through the top of the main turret 108 to the holder 130 at the holderposition 136, when the holder position 136 indexes into alignment withthe tube loading station 214 of the main circuit 116. In alternativeembodiments, the converter 100 may include an arm (not shown) movablebetween the main turret 108 and the glass tube loading turret 110. Whenthe converter 100 has converted all or a portion of the glass tube 102at a specific holder position 136, the arm may grab a new length ofglass tube 102 from the glass tube loading turret 110 or other glasstube staging device and deliver the new length of glass tube 102 to themain turret 108 at the specific holder position 136. Other methods andapparatuses for delivering new lengths of glass tube 102 to the mainturret 108 are contemplated.

Referring to FIG. 2, as previously described, the plurality ofprocessing stations 106 of the converter 100 may include one or moreheating stations 202, forming stations 204, separating stations 206,cooling stations 210, piercing stations 212, tube loading stations 214,discharge stations 216, measuring stations 218, tube length dropstations 220, or other stations and/or combinations of these stations.FIG. 2 schematically depicts the arrangement of the processing stations106 for a converter 100 having a main circuit 116 of sixteen processingstations 106 and a secondary circuit 118 of eight secondary processingstations 112. As described, the processing stations 106 of the maincircuit 116 are evenly spaced apart and evenly distributed about acircular circuit and the secondary processing stations 112 of thesecondary circuit 118 are also evenly spaced apart and evenlydistributed about a circular circuit. FIG. 2 also schematically depictsthe glass tube loading turret 110 having a plurality of loading channels132. In FIG. 2, the glass tube loading turret 110 is shown in a positionspaced apart from the main circuit 116 for purposes of illustration.Although the glass tube loading turret 110 is depicted as havingtwenty-four loading channels 132, it is understood that the glass tubeloading turret may have more or less than twenty-four loading channels132.

The main circuit 116 of the converter schematically depicted in FIG. 2may include one or more heating stations 202, a separating station 206,a piercing station 212, one or more forming stations 204, one or morecooling stations 210, a measuring station 218, a tube length dropstation 220, and a tube loading station 214. Although FIG. 2 depicts themain circuit 116 as having a circular arrangement of the processingstations 106, as previously discussed, the main circuit 116 may have theprocessing stations 106 positioned in other-shaped arrangements, such aslinear, polygonal, or other arrangements. With respect to the directionof indexing 222 of the main turret 108, the heating stations 202 may bepositioned before the separating stations 206 and each of the formingstations 204 to preheat target regions of the glass tube 102 to a targettemperature at which the target region of the glass tube 102 becomesviscous and deformable and may effectively be shaped or stretched andseparated. At the separating station 206, the formed glass article 103(FIG. 1) may be separated from the glass tube 102 (FIG. 1) as its bottomis concurrently formed. The separating station 206 may also be theprocessing station 106 at which the partially formed glass article 103,once separated, is transferred to the secondary turret 114 (FIG. 1) tobe indexed through the secondary circuit 118 of secondary processingstations 112. The piercing station 212 may be positioned on the maincircuit 116 downstream of the separating station 206 in the direction ofindexing 222 of the main turret 108. At the piercing station 212, ameniscus 350 of the glass tube 102 previously formed in the separatingstation 206 is pierced, thereby reopening the proximal end 150 of theglass tube 102.

The forming stations 204 of the main turret 108 may be positioneddownstream of the piercing station 212 in the direction of indexing 222.At the forming stations 204, the glass tube 102 is iteratively shapedinto the desired shape of the finished glass article. As noted above,one or more heating stations 202 may be positioned before each of theforming stations 204 to preheat target regions of the glass tube 102 toa temperature at which the glass tube 102 may be formed. The formingstations 204 of the main turret 108 shape the proximal end 150 (FIG. 3A)of the glass tube 102 to form one end of the glass articles 103, and theforming stations 204 of the secondary turret 114 shape the other end ofthe glass articles 103 after the glass article 103 has been separatedfrom the glass tube 102. In one or more embodiments, the converter 100may be used to produce vials from the glass tubes 102, and the formingstations 204 of the converter 100 may include one or more shoulderforming stations, one or more flange forming stations, and one or moreflange finishing stations, with one or more heating stations 202positioned before and between each of the forming stations 204. The maincircuit 116 may further include a measuring station 218, at which adimensioning system (not shown) may be used to measure one or moredimensions of the glass tube 102, such as the diameter and thickness forexample, and one or more dimensions of the features formed by theforming stations 204. Feature dimensions may include flange thickness,flange length, neck length, neck thickness, overall article length,other feature dimension, or combinations thereof. The measuring station218 may be positioned directly after the last forming station 204 sothat the dimensions are measured while the glass tube 102 is still atelevated temperature. Alternatively, the measuring station 218 may bepositioned after one or more cooling stations 210 to measure thedimensions of the glass tube 102 and/or glass article at a lowertemperature.

Still referring to FIG. 2, one or more cooling stations 210 may bepositioned after the forming stations 204 in the direction of indexing222 of the main turret 108. A tube length drop station 220 may bepositioned after the forming stations 204, between the forming stations204 and the separating station 206, to drop the partially formed glasstube 102 down, thereby positioning the glass tube 102 for separating theglass article 103 from the glass tube 102 at the separating station 206.The main circuit 116 may also include a tube loading station 214 forloading a new length of glass tube 102 feedstock from the glass tubeloading turret 110 to the main turret 108 (FIG. 1). In one or moreembodiments, the tube loading station 214 may be incorporated into acooling station 210. The tube loading station 214 may be positionedbetween the last forming station 204 and the separating station 206.

The forming stations 204 of the main turret 108 form features at a firstend of the glass article 103. For example, the forming stations 204 mayform the shoulder 142 and flange 144 at the top (first end) of a glassarticle 103 that is a vial or cartridge. Once the glass article 103 isseparated from the glass tube 102 at the separating station 206, theglass article 103 is transferred to the secondary processing stations112 of the secondary turret 114. The secondary processing stations 112may include one or more forming stations 204 for forming a second end ofthe glass article 103, which is opposite the first end of the glassarticle 103. For example, the forming stations 204 of the secondaryprocessing stations 112 may form one or more features at a bottom(second end) of the glass article 103.

The secondary processing stations of the secondary circuit may includeone or more heating stations 202, forming stations 204, polishingstations 208, cooling stations 210, discharge stations 216, or otherstations or combinations of secondary processing stations 112. AlthoughFIG. 2 depicts the secondary circuit as having a circular arrangement ofthe secondary processing stations 112, as previously discussed, thesecondary circuit may have the secondary processing stations 112positioned in other-shaped arrangements, such as linear, polygonal, orother arrangements. In one or more embodiments, the secondary processingstations 112 of the secondary circuit 118 may be used to form one ormore features of the glass article 103, such as a vial, ampoule,cartridge, or syringe, for example, at an end of the glass article 103opposite the end formed by the main turret 108. For example, in someembodiments, the glass article 103 is a vial and the forming stations204 of the secondary circuit 118 may form the bottom of the vial. Otherfeatures are also contemplated such as those features characteristic ofampoules, cartridges, syringes, and the like. The secondary circuit 118may include one or more polishing stations 208 to finish the surface ofthe glass article. The secondary circuit 118 may further include aplurality of cooling stations 210 and the discharge station 216, atwhich station the finished glass article 103 may be discharged from theconverter 100.

The previous description of the processing stations 106 of the maincircuit 116 and the secondary processing stations 112 of the secondarycircuit 118 may represent a typical converter 100 for producing vialsfrom the glass tube 102. However, it is understood that more or fewerprocessing stations 106 and secondary processing stations 112 may beutilized to make vials having different shapes or other glass articles,such as cartridges, syringes, ampoules, or other glass articles.Additionally, it is understood that the processing stations 106 andsecondary processing stations 112 may be arranged in any of a number ofdifferent orders and/or configurations in order to produce differentlyshaped glass articles.

Referring now to FIG. 3A, a heating station 202 of the converter 100 isschematically depicted. Each of the heating stations 202 may include oneor more heating elements 301. As illustrated in FIG. 3A, in embodiments,the heating element 301 may include one or more burners 302, which areused to heat targeted regions of the glass tube 102 prior to a formingoperation performed at the forming station 204 (FIG. 2) or separatingoperation performed at the separating station 206 (FIG. 2). AlthoughFIG. 3A depicts a single burner 302, it is understood that more than oneburner 302 may be employed in a single heating station 202. Each burner302 may be fluidly coupled to a fuel supply 304, an oxygen supply 306,and, optionally, an air supply 308. Examples of fuels for the burner mayinclude, but are not limited to hydrogen, hydrocarbon fuel gases such asmethane, propane, and butane for example, other fuels, or combinationsof these. Each burner 302 may include a fuel control valve 310 tocontrol the flow rate of fuel gas to the burner 302. Each burner 302 mayalso include an oxygen control valve 312 to control the mass flow rateof oxygen to the burner 302. Each burner 302 may further include an aircontrol valve 314 for optionally controlling a flow rate of air to theburner 302. The burner 302 combusts the fuel gas in the presence ofoxygen and/or air to produce a flame that heats at least the targetregion of the glass tube 102. Although the heating stations 202 of theconverter 100 are described herein as heating the glass tube 102 usingburners, it is understood that other heating elements or methods otherthan burners may be used to heat the glass tube 102.

Referring now to FIGS. 3B and 3C, examples of forming stations 204 ofthe converter 100 are schematically depicted. Each forming station 204may include one or more forming tools 324. The forming tools 324 may berotatable relative to the base 104 (FIG. 1) about tooling axis E, whichare generally parallel to the central axis A (FIG. 1) of the main turret108 (FIG. 1). When indexed into the forming station 204, the glass tube102, which has been heated in a prior heating station 202, is rotated bythe holder 130. The forming tools 324 are engaged with the outer surface140 of the glass tube 102. Contact of the forming tools 324 with theouter surface 140 of the heated glass tube 102 forms the glass tube 102into the desired shape. Upon expiration of the contact time, the formingtool actuators 326 withdraw the forming tools 324 from engagement withthe glass tube 102.

FIG. 3B schematically illustrates an embodiment of a forming station 204for forming the shoulder 142 of a glass vial formed from the glass tube102. FIG. 3C schematically depicts an exemplary embodiment of a formingstation 204′ for forming the flange 144 of a glass vial formed from theglass tube 102. The forming station 204′ for forming the flange 144comprises three forming tools 324 a, 324 b, and 324 c. Two of theforming tools 324 a and 324 b contact the outer surface 140 of the glasstube 102 to form the outer contour of the flange 144. The third formingtool 324 c contacts the inner surface of the glass tube 102 radiallyinward of the flange 144 to form the inner diameter of the glass tube102 at the flange 144. The third forming tool 324 c also contacts theaxial end of the glass tube 102 to form the axial surface of the flange144. In embodiments, the third forming tool 324 c may be stationary andthe glass tube 102 rotated about the third forming tool 324 c by theholder 130. In embodiments, a thin layer of lubricant, such as oil forexample, may be disposed between the glass tube 102 and the thirdforming tool 324 c to separate the glass tube 102 from making contactwith the third forming tool 324 c.

FIG. 3D schematically depicts a cooling station 210 having one or morecooling nozzles 340 positioned to direct a cooling fluid 342, such aschilled air or an inert gas for example, towards the glass tube 102. Oneor more of the cooling nozzles 340 may be positioned to direct thecooling fluid 342 to specific regions of the glass tube 102. One or morecooling fluid control valves 344 may be fluidly coupled to the coolingnozzles 340 to control the mass flow rate of cooling fluid 342 to thecooling nozzles 340, which enable control of the rate of cooling of theglass tube 102 as well as the temperature of the glass tube 102 andtemperature gradients in the glass tube 102.

Referring now to FIG. 3E, a separating station 206 of the converter 100is schematically depicted. The separating station 206 depicted in FIG.3E is a thermal separation station and is positioned after one or moreheating stations 202 in the direction of indexing 222 of the main turret108. The heating stations 202 positioned before the separating station206 heat the glass tube 102 to make the glass viscously deformable. Theseparating station 206 may include a separating burner 348. While theglass tube 102, which has been made viscously deformable by the previousheating stations 202, is rotated by the holder 130 about the holder axisD, the separating burner 348 may be engaged with the outer surface 140of the glass tube 102 to cut the glass tube 102 to a target length,thereby separating an article 103 (FIG. 1) from the glass tube 102. Onceseparated from the glass tube 102, the article 103 may be transferred tothe secondary turret 114 (FIG. 1) or discharged from the converter 100.Although shown in FIG. 3E as a thermal separating station, theseparating station 206 may also be a non-thermal separating station suchas a separating station using score and break techniques, as may be usedfor syringes and cartridges for example.

Referring now to FIG. 3F, a typical piercing station 212 of theconverter 100 is schematically depicted. The piercing station 212 ispositioned after the separating station 206 in the direction of indexing222 of the main turret 108. As previously described, thermal separationof the article 103 from the glass tube 102 in the separating station 206may cause a meniscus 350 of glass to form across the proximal end 150 ofthe glass tube 102. The piercing station 212 may include a piercingburner 352. The piercing burner 352 may be positioned below the proximalend 150 of the glass tube 102 and may be oriented toward the proximalend 150 of the glass tube 102. The piercing burner 352 may be fluidlycoupled to one or more of a fuel gas supply 304, oxygen supply 306, airsupply 308, or combinations of these. The fuel gas supply 304, theoxygen supply 306, and the air supply 308 were previously discussed inrelation to the burner 302 of FIG. 3A. When main turret 108 indexes theglass tube 102 into the piercing station 212, the flame from thepiercing burner 352 heats the meniscus 350 of glass and melts themeniscus 350 to pierce the meniscus 350 of glass and re-open theproximal end 150 of the glass tube 102. The heat from the piercingburner 352 creates a chimney effect in the internal volume of the glasstube 102. Additionally, gas flow out of the piercing burner 352 may alsocause convection of gases and vapors upward in the internal volume ofthe glass tube 102

FIGS. 3A-3F include schematic illustrations of several differentexamples of processing stations 106 that may be utilized in theconverter 100. However, it should be understood that other processingstations 106 having different structures, combinations of structures, orfunctions, may be utilized to achieve the desired conversion of theglass tube 102 into one or more glass articles.

Referring again to FIG. 2, in operation, the main turret 108 indexes theglass tubes 102, which are secured in the holders 130, into a processingstation 106. A specific operation, such as heating, forming, piercing,separating, cooling, dropping, feeding, etc., is performed on the glasstubes 102 at each of the processing stations 106. As used herein, a“dwell time” of the converter 100 refers to the time that the glass tube102 spends in a particular processing station 106 before being indexedby the main turret 108 to the next subsequent processing station 106.The converter 100 may be tuned so that all of the processing stations106 complete their operations within the dwell time. At the end of thedwell time, the main turret 108 indexes the glass tubes 102 to the nextprocessing stations 106. As used herein, the “index time” refers to thetime that it takes for the main turret 108 to index the glass tubes 102from one processing station 106 to the next processing station 106 andis measured in units of time. The total time per part per station, asused in this disclosure, is the sum of the dwell time and the indextime.

Examples of converters 100 for converting glass tube 102 into glassvials include the Vial Forming Machine Model RP16 with Automatic TubeFeeder manufactured by AMBEG Dr. J. Dichter GmbH, which includes sixteenprocessing stations 106 in the main circuit 116 and eight secondaryprocessing stations 112. Other examples include the Vial Forming MachineModel RP32 manufactured by AMBEG Dr. J. Dichter GmbH, which hasthirty-two processing stations 106 in the main circuit 116 and twosecondary circuits 118 with eight secondary processing stations 112 ineach secondary circuit 118, and the Zeta 098 Vial Forming Machinemanufactured by Euromatic S.R.L., which has 36 processing stations.Another example may include the Zeta 103 Cartridge Forming Machinemanufactured by Euromatic S.R.L., which is a converter for convertingglass tube into cartridges. The cartridge converter has similarcharacteristics to the previously described vial converters 100 but isutilized to produce glass articles having a cartridge form factor ratherthan a vial.

Although described in the context of a converter 100 for producing glassvials from glass tube 102, it should be understood that the converter100 may be configured to produce one or more other articles, such ascartridges, syringes, ampoules, or other glass articles, by changing theforming tools 324 and/or the order or configuration of processingstations 106 in the main circuit 116 or secondary processing stations112 in one or more secondary circuits 118.

During the converting process, the glass tube 102 may be heated totemperatures that may be equal to or greater than 1500° C. Heating theglass tube 102 to temperatures of 1500° C. or greater may cause one ormore volatile constituents of the glass composition of the glass tube102 to vaporize and diffuse into the atmosphere or into the internalvolume of the glass tube 102. For some aluminosilicate glasscompositions, the volatile constituents vaporized during the convertingprocess may include sodium. For borosilicate glass compositions thevolatile constituents may also include boron in addition to sodium.Other volatile constituents may also vaporize from the glass compositionduring converting.

These volatile constituents may be transported upward through the glasstube 102 due to a “chimney effect” caused by the heated gases in theglass tube 102 rising upward. Heating the gases inside the glass tube102 reduces the density of the gases, which causes the heated gases torise upward through the internal volume of the glass tube 102 throughbuoyancy forces. For example, referring to FIG. 3F, at the piercingstation 212, the piercing burner 352 may be used to heat and open themeniscus 350 formed over the proximal end 150 of the glass tube 102 inthe separating station 206. The piercing burner 352 may be generallyoriented vertically upward (i.e., in the +Z direction of the coordinateaxis in FIG. 3F) so that the flame extends from the piercing burner 352generally vertically upward to impinge upon the meniscus 350 of theglass tube 102. The vertical orientation of the piercing burner 352 mayincrease the chimney effect at the piercing station 212 by directing hotcombustion gases upward through the glass tube 102. Thus, in thepiercing station 212, the chimney effect may be further increased due toconvection of hot combustion gases upward through the glass tube 102caused by the piercing burner 352. For other processing stations 106,such as the separating station 206, one of the heating stations 202,and/or one of the forming stations 204, the chimney effect may be causedprimarily by the reduced density of the heated gases inside the glasstube 102. The increased chimney effect in the piercing station 212 dueto convection caused by the piercing burner 352 may result in thevaporized volatile constituents traveling farther upward through theglass tube 102 before condensing on the interior surface 146 of theglass tube 102 compared to the other processing stations 106.

As the heated gases travel upward through the glass tube 102 due to thechimney effect, the vaporized volatile constituents in the gases cooland may condense on the interior surfaces 146 (FIG. 4) of the glass tube102. As the volatile constituents condense on the interior surface 146of the glass tube 102, the volatile constituents may react to formdeposits on the interior surface 146 of the glass tube 102. For example,for a glass composition comprising sodium, the sodium vapors condensingon the interior surface 146 of the glass tube 102 may react at theinterior surface 146 to form one or a plurality of sodium compoundsdeposited onto the interior surface 146 of the glass tube 102. Thesedeposits from condensation of the volatile constituents on the interiorsurface 146 of the glass tube 102 may continue to build up as the glasstube 102 is indexed multiple times through the processing stations 106of the converter 100. As previously discussed, the buildup of thesedeposits on the interior surface 146 of the glass tube 102 may increasethe SHR of the glass articles 103 produced from the glass tube 102.

The systems and methods disclosed herein may reduce or eliminate theformation of deposits on the interior surface 146 of the glass tube 102by producing a flow of a gas through the glass tube 102 from the distalend 152 to the proximal end 150 of the glass tube 102 (i.e., the −Zdirection of the coordinate axis of FIG. 5). Producing a flow of gasthrough the glass tube 102 towards the proximal end 150 of the glasstube 102 may counteract the chimney effect caused by heating the gasesinside the glass tube 102 and may reduce or prevent vaporized volatileconstituents from traveling upward through the glass tube 102 andcondensing on the interior surface 146 of the glass tube 102.Additionally or alternatively, in other embodiments, the systems andmethods disclosed herein may reduce or eliminate the formation ofdeposits on the interior surface 146 of the glass tube 102 by using thegas flow to pierce/open the meniscus 350 and eliminating the piercingburner 352 at the piercing station 212.

Referring to FIGS. 5-7, the converter 100 may include a gas flow system500 configured to deliver a flow of a gas into the distal end 152 of theglass tube 102 for a discrete duration of time, thereby creating a flowof gas through the glass tube 102 from the distal end 152 to theproximal end 150. The flow of gas through the glass tube 102 produced bythe gas flow system 500 may counteract the chimney effect in the glasstube 102. Alternatively or additionally, in some embodiments, the gasflow system 500 may produce a flow of gas through the glass tube 102sufficient to pierce the meniscus 350 formed at the proximal end 150 ofthe glass tube 102 following separation of the glass article 103 fromthe glass tube 102 at the separating station 206. The gas flow system500 may include a gas source 504 and at least one gas delivery assembly502 coupled to at least one processing station 106 or to each of theplurality of holders 130 of the main turret 108. The gas from the gassource 504 may include compressed air, inert gas, other gas, orcombination of gases. In some embodiments, the gas of the gas source maybe an inert gas, such as argon for example, which may further reduce theprobability of forming deposits on the interior surface 146 of the glasstube 102.

Referring to FIG. 5, in some embodiments, the gas delivery assembly 502may include a nozzle 506 positioned to deliver gas from the gas source504 into the distal end 152 of the glass tube 102, which may be securedin a holder 130. The gas delivery assembly 502 may also include a valve508 fluidly coupled to the nozzle 506. The valve 508 may be fluidlycoupled to the gas source 504 so that gas from the gas source 504 mayflow through the valve 508 to the nozzle 506 when the valve 508 is in anopen position. The valve 508 may be fluidly coupled to the gas source504 by a flexible conduit 512, which may allow a position of the gasdelivery assembly 502 to move relative to the gas source 504. The gasdelivery assembly 502 may include a valve actuator 510 operativelycoupled to the valve 508 to open and close the valve 508 to control theflow of gas to the nozzle 506. The valve actuator 510 may be a pneumaticactuator, electric actuator, hydraulic actuator, electromagneticactuator, or other type of actuator. In some embodiments, the valveactuator 510 may be a solenoid.

The nozzle 506 may be any suitable type of nozzle. In some embodiments,the nozzle 506 may be small enough to fit inside of the distal end 152of the glass tube 102. In some embodiments, the nozzle 506 may bedecoupled from the distal end 152 of the glass tube 102.

The gas delivery assembly 502 may include a positioner 520 coupled tothe nozzle 506 and movable to position the nozzle 506 relative to thedistal end 152 of the glass tube 102. As previously discussed, eachcycle of the converter 100 includes removal of a glass article 103 fromthe length of the glass tube 102, thereby reducing the length of theglass tube 102. The length of the glass tube 102 decreases with eachcycle of the glass tube 102 through the processing stations 106 of theconverter 100. As the length of the glass tube 102 decreases, theposition of the distal end 152 of the glass tube 102 changes (i.e.,moves in the −Z direction according to the coordinate axis in FIG. 5).

Referring to FIG. 5, to account for the decreasing length of the glasstube 102 and changing vertical position of the distal end 152, thepositioning system 520 may be operable to translate the nozzle 506 inthe vertical direction (i.e., the +/−Z direction of the coordinate axisof FIG. 5) relative to the distal end 152 of the glass tube 102. In someembodiments, the positioning system 520 may be operable to position thenozzle 506 proximate the distal end 152 of the glass tube 102 until theglass tube 102 is consumed below the level of the holder 130. Once theglass tube 102 is consumed below the level of the holder 130, leakage ofgas from the nozzle 506 may occur in the holder 130 so that less of thegas flow from the nozzle 506 enters the distal end 152 of the glass tube102. In some embodiments, the positioning system 520 may include a rail522 and a bracket 524 movable along the rail 522. In some embodiments,the rail 522 may be coupled to the base 104 of the converter 100 at aspecific processing station 106, such as the piercing station 212 or theseparating station 206 for example, so that the rail 522 is stationaryand does not rotate with the main turret 108 or otherwise move with theglass tube 102 from processing station 106 to processing station 106.Alternatively, in other embodiments, the rail 522 may be coupled to themain turret 108 for rotation with the main turret 108 through theplurality of processing stations 106. The rail 522 may be orientedgenerally parallel to the glass tube 102. For example, in someembodiments, the rail 522 may be oriented generally vertically (i.e., inthe +/−Z direction of the coordinate axis of FIG. 5).

The positioning system 520 may include a servo motor 528 coupled to thebracket 524 and moveably engaged with the rail 522 to allow for movementof the bracket 524 along the rail 522 by the servo motor 528. Althoughdepicted and described as including a rail and bracket movable along therail by the servo motor 528, it is understood that other types ofpositioning systems may be used to translate the nozzle 506 in thevertical direction (i.e., the +/−Z direction of the coordinate axis inFIG. 5) relative to the glass tube 102.

Still referring to FIG. 5, the nozzle 506 may be coupled to the bracket524. In some embodiments, the nozzle 506 may be non-rigidly coupled tothe bracket 524, such as by a spring loaded coupling. Non-rigidlycoupling the nozzle 506 to the bracket 524 may prevent breakage of theglass tube 102 if the nozzle 506 makes contact with the glass tube 102while indexing the glass tube 102 into or out of the processing station106. Additionally, in some embodiments, the valve 508 and/or the valveactuator 510 may also be coupled to the bracket 524. The bracket 524 mayposition the nozzle 506 vertically above the distal end 152 of the glasstube 102 so that the nozzle 506 delivers the gas downward (i.e., the −Zdirection of the coordinate axis in FIG. 5) directly into the distal end152 of the glass tube 102. Translation of the bracket 524 along the rail522 may move the nozzle 506 in the +/−Z direction of the coordinate axisof FIG. 5 to position the nozzle 506 relative to the distal end 152 ofthe glass tube 102.

The positioning system 520 may include a sensor 526 positioned to detectthe vertical position of the distal end 152 of the glass tube 102. Insome embodiments, the sensor 526 may be coupled to the bracket 524.Alternatively, the sensor 526 may be mechanically coupled to thepositioner 528, the valve actuator 510, the valve 508, the nozzle 506,or other component of the gas delivery assembly 502. The sensor 526 maybe oriented towards the glass tube 102 and may determine when the nozzle506 is properly positioned relative to the distal end 152 of the glasstube 102. Examples of sensors may include, but are not limited to,proximity sensors (photo eye), light shields, other sensors, orcombinations of sensors. The sensor 526 may be communicatively coupledto the positioner 528, which may be operable to position the nozzle 506relative to the distal end 152 of the glass tube 102 in response to asignal from the sensor 526.

The positioning system 520 may position the nozzle 506 a distance G1from the distal end 152 of the glass tube 102. The distance G1 from thenozzle 506 to the distal end 152 of the glass tube 102 may be small aspossible to enable the nozzle 506 to deliver the gas into the glass tube102 with minimal loss of gas outside the glass tube 102. Reducing thedistance G1 from the nozzle 506 to the distal end 152 of the glass tube102 may reduce the volume flow rate of gas required to evacuate thevaporized volatile constituents from the internal volume of the glasstube 102 and/or pierce the meniscus 350 of the glass tube 102.Conversely, increasing the distance G1 from the nozzle 506 to the distalend 152 of the glass tube 102 may increase the volume flow rate of gasrequired to evacuate the vaporized constituents from the internal volumeof the glass tube 102 and/or pierce the meniscus 350 of the glass tube102. In some embodiments, the distance G1 from the nozzle 506 to thedistal end 152 of the glass tube 102 may be from 1 millimeter (mm) to 15mm or more. In some embodiments, the gas delivery assembly 502 may becoupled to the base 104 of the converter 100 or to a stationarystructure so that the gas delivery assembly 502 is positioned at aspecific processing station 106. For example, the gas delivery assembly502 may be positioned at the piercing station 212, the separatingstation 206, one of the heating stations 202, and/or one of the formingstations 204. In some embodiments, the gas flow system 500 may include aplurality of gas delivery assemblies 502, each positioned at a differentprocessing station 106. For example, the gas flow system 500 may includea gas delivery assembly 502 positioned at the piercing station 212 andanother gas delivery assembly positioned at the separating station 206.Additional gas delivery assemblies 502 may be positioned at one or moreheating stations 202 and/or forming stations 204.

FIG. 5 illustrates the gas delivery assembly 502 positioned at thepiercing station 212 of the converter 100. In operation, the converter100 may index the glass tube 102 into the piercing station 212 havingthe gas delivery assembly 502 (e.g., the piercing station 212 of FIG.5). Once the glass tube 102 is in position in the piercing station 212,the positioning system 520 may move the bracket 524 along the rail 522to position the nozzle 506 proximate to the distal end 152 of the glasstube 102. The converter 100 may operate the piercing burner 352 topierce the meniscus 350 formed over the proximal end 150 of the glasstube 102 in the preceding separating station 206. Immediately followingpiercing of the meniscus 350, the valve actuator 510 may be operated toopen the valve 508, which may allow gas from the gas source 504 to flowthrough the valve 508, through the nozzle 506, and into the distal end152 of the glass tube 102. The flow of gas into the distal end 152 ofthe glass tube 102 may cause the gas to flow downward (i.e., in the −Zdirection of the coordinate axis of FIG. 5) through the glass tube 102to counteract the chimney effect and prevent vaporized volatileconstituents from traveling upward (i.e., +Z direction of the coordinateaxis of FIG. 5) through the glass tube 102 and depositing on theinterior surface 146 of the glass tube 102. After a set duration oftime, the valve actuator 510 may operate to close the valve 508, whichmay reduce and/or stop the flow of gas into the glass tube 102. Thevalve actuator 510 in combination with the valve 508 may be used tocontrol the volume flow rate of the gas through the nozzle 506.

The volume flow rate of gas from the nozzle 506 into the glass tube 102may be sufficient to counteract the chimney effect and produce a netdownward (i.e., −Z direction of the coordinate axis of FIG. 5) flow ofgas through the glass tube 102. The flow rate and/or pressure of the gasfrom the nozzle 506 may depend on the size of the glass tube 102, suchas the inside diameter ID (FIG. 4) of the glass tube. The volume flowrate and or pressure of the gas may also depend on other processconditions of the converter 100, such as process speed, converter setup,or glass type.

The valve actuator 510 may maintain the valve 508 in an open positionfor a discrete duration of time to produce a gas pulse through the glasstube 102. In some embodiments, the pulse duration of the gas pulse maybe less than the time required for the main turret 108 to cycle oncethrough all of the processing stations 106. Alternatively, in otherembodiments, the pulse duration may be less than the dwell time of theconverter 100. In still other embodiments, the pulse duration may beless than the index time of the converter 100. The pulse duration may beinfluenced by the inner diameter ID of the glass tube 102, the processspeed, the converter setup, and the glass type.

Although described in the context of the piercing station 212, it isunderstood that the gas delivery assembly 502 may operate in a similarmanner to evacuate the internal volume of the glass tube 102, when thegas delivery assembly 502 is coupled to other processing stations 106,such as the separating station 206, one of the heating stations 202, orone of the forming stations 204. Alternatively, the gas deliveryassembly 502 may be configured to pierce the meniscus 350 of the glasstube 102 at the piercing station 212 or the separating station 206. Forexample, when the gas delivery assembly 502 is positioned at thepiercing station 212, the gas delivery assembly 502 may be configured todeliver gas flow sufficient to pierce the meniscus 350, which may allowfor removal of the piercing burner 352 from the piercing station 212. Insome embodiments, the gas delivery assembly 502 may be positioned at theseparating station 206 and may be configured to deliver a pulse of gassufficient to pierce the meniscus 350 immediately following separationof the glass article 103 from the glass tube 102. In these embodiments,the valve actuator 510 of the gas delivery assembly 502 may operate toopen the valve 508 immediately following separation of the article 103from the glass tube 102 to pierce the meniscus 350 before the end of thedwell time of the glass tube 102 in the separating station 206. Bypiercing the meniscus 350 in the separating station 206 with the gasdelivery assembly 502, the piercing station 212 may be eliminated fromthe converter 100 or reconfigured into a different type of processingstation, such as a heating station 202, forming station 204, coolingstation 210, measuring station 218, or other processing station 106.Eliminating the piercing burner 352 may result in substantialimprovement in SHR performance of glass articles 103 produced from theglass tube 102. In some embodiments, eliminating the piercing station212 altogether may improve the efficiency of the converter 100 byreducing the number of processing stations 106, thereby enabling fasterconverting and increased throughput.

When the gas delivery assembly 502 is employed to pierce the meniscus350 of the glass tube 102, the volume flow rate of gas may be sufficientto pierce the meniscus 350 of the glass tube 102. However, if the volumeflow rate of gas through the glass tube 102 becomes too great, the gasflow may result in destructive piercing of the meniscus 350, which mayproduce quenched glass particles ejected from the proximal end 150 ofthe glass tube 102.

In some embodiments, the gas flow system 500 may include a plurality ofgas delivery assemblies 502 with each of the gas delivery assemblies 502coupled to a holder 130 so that the gas delivery assemblies 502 areindexed with the glass tube 102 through all of the processing stations106. In these alternative embodiments, the flexible conduits 512 maycouple each of the gas delivery assemblies to a gas manifold 560 (SeeFIG. 8). The gas manifold 560 may be coupled to the gas source 504. Insome embodiments, the manifold 560 may be coupled to the gas source 504through a rotating union 564 (FIG. 8), which may allow the gas manifold560 to rotate with the main turret 108 and the plurality of gas deliveryassemblies 502 coupled thereto. In some embodiments, the gas deliveryassemblies 502 may be coupled to the main turret 108 at positionscorresponding to each of the holders 130.

Referring to FIGS. 6A, 6B, and 6C, an alternative embodiment of a gasdelivery assembly 502 a of the gas flow system 500 is schematicallydepicted. The gas delivery assembly 502 a may include a cylindricalmount 530 and the nozzle 506 may be coupled to the cylindrical mount530. The cylindrical mount 530 may be removeably coupleable directly tothe distal end 152 of the glass tube 102. For example, as shown in FIGS.6A and 6B, the cylindrical mount 530 may include a clamp 532 positionedto secure the cylindrical mount 530 to and around the outer surface 140of the glass tube 102. Alternatively, as shown in FIG. 6C, thecylindrical mount 530 may have a set screw 538 to secure the cylindricalmount 530 to the distal end 152 if the glass tube 102. Other methods andstructures available in the art for removably coupling the cylindricalmount 530 to the outer surface 140 of the glass tube 102 are alsocontemplated. The cylindrical mount 530 may position the nozzle 506proximate to the distal end 152 of the glass tube 102. For example, insome embodiments, the cylindrical mount 530 may position the nozzle 506so that the nozzle 506 is spaced apart from the distal end 152 of theglass tube 102 by the distance G1, previously described in relation toFIG. 5. As shown in FIGS. 6A, 6B, and 6C, the cylindrical mount 530 mayalso include one or a plurality of open vents 534. The open vents 534may prevent over-pressuring the glass tube 102 when utilizing the gasflow system 500 to purge the internal volume of the glass tube 102.

Still referring to FIGS. 6A, 6B, and 6C, the nozzle 506 may be coupledto the flexible conduit 512 by a swivel connector 536. The swivelconnector 536 may allow rotation of the cylindrical mount 530 and nozzle506 relative to the flexible conduit 512. Through engagement of thecylindrical mount 530 with the distal end 152 of the glass tube 102, thegas flow system 500 a may travel with the glass tube 102 as the glasstube 102 is indexed through the plurality of processing stations 106 ofthe converter 100. When the glass tube 102 is consumed after multiplerotations of the main turret 108 through the plurality of processingstations 106, the cylindrical mount 530 may be removed from the distalend 152 of the glass tube 102 so that a new glass tube 102 may be loadedin the holder 130. Once the new glass tube 102 is loaded into the holder130, the cylindrical mount 530 may be coupled to the distal end 152 ofthe new glass tube 102. In some embodiments, the cylindrical mount 530may be manually removed from the glass tube 102 and installed on a newglass tube 102 during tube loading. Because the cylindrical mount 530 ofthe gas delivery assembly 502 is coupleable directly to the distal end152 of the glass tube 102, the cylindrical mount 530 may eliminate theneed to change the position of the nozzle 506 after each cycle of themain turret 108 to account for the decreasing length of the glass tube102.

Referring to FIG. 7, in another embodiment of the gas flow system 500 a,the gas delivery assembly 502 may include an enclosure 540 positioned toenclose the distal end 152 of the glass tube 102 extending from theholder 130. The enclosure 540 may completely surround the distal end 152of the glass tube 102 above the main turret 108 so that the glass tube102 above the holder 130 is contained with the enclosure 540. A gaspulse may be introduced to an internal volume of the enclosure 540 andmay produce a flow of gas vertically downward (i.e., −Z direction of thecoordinate axis of FIG. 7) through the glass tube 102. This verticallydownward flow of gas through the glass tube 102 may counteract thechimney effect in the glass tube 102 to reduce or prevent vaporizedvolatile constituents from passing up the glass tube 102 and condensingon the interior surfaces 146 of the glass tube 102. The gas pulseintroduced to the enclosure 540 may also be sufficient to pierce themeniscus 350 of the glass tube 102 produced during separation of thearticle 103 from the glass tube 102. Additionally, the enclosure 540 mayprevent upward flow of vaporized volatile constituents outside of theglass tube 102 from contacting and condensing on the exterior surfacesof the glass tube 102. Thus, the enclosure 540 may prevent the depositsof volatile constituents on the exterior surfaces of the glass tube 102.

Referring to FIG. 7, the enclosure 540 may have a proximal end 550coupled to the holder 130 and a distal end 552 that extends above thedistal end 152 of the glass tube 102. Coupling the proximal end 550 ofthe enclosure 540 to the holder 130 may cause the enclosure 540 totravel with the holder 130 through the plurality of processing stations106 by rotation of the main turret 108. The proximal end 550 of theenclosure 540 may include a seal (not shown) between the proximal end550 and the holder 130. The seal may create a gas-tight seal to preventgas introduced to the enclosure 540 from leaking out from between thedistal end 552 and the holder 130. The enclosure 540 may be made from arigid material. In embodiments, the rigid material of the enclosure 540may be gas impermeable and heat resistant. Examples of rigid materialsmay include, but are not limited to, metals (e.g., steel, aluminum,Inconel, or other metal or metal alloy), glass, heat resistant polymericmaterial, or other material. In some embodiments, the enclosure 540 maybe generally cylindrical in shape. Although described as beingcylindrical in shape, the enclosure 540 may have any other convenientshape as long as the enclosure 540 completely surrounds the glass tube102 secured in the holder 130.

The enclosure 540 may include a cap 542 that may be removably coupleableto the distal end 552 of the enclosure 540. The enclosure 540 mayinclude a cap seal (not shown) disposed between the cap 542 and thedistal end 552 of the enclosure 540. The cap seal may produce agas-tight seal between the cap 542 and the distal end 552 of theenclosure 540 to prevent gas from leaking out of the enclosure 540. Thecap 542 may be coupled to the enclosure 540 by a hinge 543, lever,swivel, or other coupling capable of allowing the cap 542 to be movedaway from engagement with the distal end 552 of the enclosure 540 andreplaced during tube loading. In some embodiment, the gas flow system500 a may include a device (not shown) for opening and closing the cap542 of the enclosure 540 during tube loading. The device for opening andclosing the cap 542 may be any mechanical, electromechanical, pneumatic,magnetic, or other device capable of moving the cap 542 into and out ofengagement with the enclosure 540. For example, in some embodiments, thecap 542 may be a split cap comprising two parts that are spring loadedso that, during tube loading, the two parts of the split cap may beelectro-mechanically spread apart via arms, and after tube loading, thespring may bring the two parts back together. In some embodiments, thecap 542 may be manually disengaged from the enclosure 540 during tubeloading.

The cap 542 may have a central bore extending vertically (i.e., in the+/−Z direction of the coordinate axis of FIG. 7) through the cap 542.The cap 542 may further include a swivel connector 544 disposed withinthe central bore and fluidly coupled to a flexible conduit 546. Theenclosure 540, the cap 542, and the holder 130 may define an internalvolume of the enclosure 540. The internal volume of the enclosure 540may be in fluid communication with the distal end 152 of the glass tube102 when the glass tube 102 is inside of the enclosure 540. In otherwords, the enclosure 540 may completely surround and enclose the distalend 152 of the glass tube 102.

Still referring to FIG. 7, the gas delivery assembly 502 may furtherinclude the valve 508. The flexible conduit 546 may be coupled to thevalve 508 to fluidly couple the valve 508 to the enclosure 540 throughthe central bore of the cap 542. The swivel connector 544 may allow forrotation of the flexible conduit 546 relative to the enclosure 540, suchas when the enclosure 540 rotates with the main turret 108 and/or withthe holder 130. The valve 508 may be fluidly coupled to the gas source504 so that gas from the gas source 504 may flow through the valve 508,through the flexible conduit 546, and into the enclosure 540 through theswivel connector 544. The valve 508 may be fluidly coupled to the gassource 504 by a flexible conduit 512, which may allow a position of thegas delivery assembly 502 to move relative to the gas source 504. Thegas delivery assembly 502 may include a valve actuator 510, such as asolenoid for example, operatively coupled to the valve 508 to open andclose the valve 508 to control the flow of gas to the enclosure 540.

Referring now to FIG. 8, the gas flow system 500 a may include aplurality of gas delivery assemblies 502. The enclosures 540 of the gasdelivery assemblies 502 may be coupled to the holders 130 at everyposition on the main turret 108 so that each glass tube 102 secured in aholder 130 is enclosed within one of the enclosures 540. The gas flowsystem 500 a may include a manifold 560 having a plurality of gasconnections 566. In some embodiments, the manifold 560 may be positionedgenerally above (i.e., in the +Z direction of the coordinate axis ofFIG. 8) relative to the main turret 108. In some embodiments, themanifold 560 may be coupled to the main turret 108 for rotation with themain turret 108. Although the manifold 560 is depicted in FIG. 8 anddescribed herein as being circular in shape, the manifold 560 may alsobe non-circular when used with a non-circular converter. For example,for a linear converter, the manifold 560 may be linear. The valve 508 ofeach of the enclosures 540 may be fluidly coupled to one of the gasconnections 566 of the manifold 560. The manifold 560 may be fluidlycoupled to the gas source 504 through a gas supply conduit 562. In someembodiments, the gas supply conduit 562 and/or the manifold 560 may befluidly coupled to the gas source 504 through a rotating union 564. Forembodiments in which the processing stations 106 are arranged in acircular pattern, the rotating union 564 may allow the manifold 560 torotate with the main turret 108 while simultaneously receiving the gasfrom the gas source 504 and distributing the gas to the gas deliveryassemblies 502. The manifold 560 may have a plurality of connections(not shown) for mechanically and/or fluidly coupling each of the valves508 to the manifold 560.

Referring back to FIG. 7, the gas flow system 500 a may be operable todeliver a gas pulse to the enclosure 540 at one or more processingstations 106 to evacuate the internal volume of the glass tube 102 toreduce or prevent deposits of volatile components from forming on theinterior surface 146 of the glass tube 102. FIG. 7 illustrates the gasdelivery assembly 502 coupled to the holder 130 positioned in thepiercing station 212 of the converter 100. In operation, the converter100 may index the glass tube 102 into the piercing station 212 havingthe gas delivery assembly 502 (e.g., the piercing station 212 of FIG.5). Once the glass tube 102 is in position in the piercing station 212,the converter 100 may operate the piercing burner 352 to open themeniscus 350 formed over the proximal end 150 of the glass tube 102 inthe preceding separating station 206. Immediately following opening ofthe meniscus 350, the valve actuator 510 may be operated to open thevalve 508, which may allow gas to flow from the manifold 560, throughthe valve 508, through the flexible conduit 546, and into the enclosure540. Gas flow into the enclosure 540 may cause gas to flow from theenclosure 540 into the distal end 152 of the glass tube 102. The flow ofgas into the glass tube 102 may cause the gases to flow downward (i.e.,in the −Z direction of the coordinate axis of FIG. 5) through the glasstube 102 to counteract the chimney effect and prevent vaporized volatileconstituents from traveling upward (i.e., +Z direction) through theglass tube 102 and depositing on the interior surface 146 of the glasstube 102. After a set duration of time, the valve actuator 510 mayoperate to close the valve 508, which may reduce and/or stop the flow ofgas into the glass tube 102. The valve actuator 510 in combination withthe valve 508 may be used to control the volume flow rate of the gasthrough the nozzle 506.

The volume flow rate of gas from the enclosure 540 into the glass tube102 may be sufficient to counteract the chimney effect and produce a netdownward (i.e., −Z direction) flow of gas through the glass tube 102.Additionally, the volume flow rate of gas sufficient to counteract thechimney effect in the glass tube 102 may be proportional to the innerdiameter ID (FIG. 4) of the glass tube 102. The volume flow rate of gasmay be influenced by the inner diameter ID of the glass tube 102, thedimensions of the enclosure 540, the process speed, the converter setup,and/or the type of glass. For example, a glass tube 102 having a greaterinner diameter may require a greater volume flow rate of gas tocounteract the chimney effect compared to a glass tube 102 having asmaller inner diameter.

As previously discussed, each cycle of the converter 100 includesremoval of a glass article 103 from the length of the glass tube 102,reducing the length of the glass tube 102. The length of the glass tube102 decreases with each cycle of the glass tube 102 through theprocessing stations 106 of the converter 100. The gas flow system 500 ahaving the gas delivery assemblies 502 with the enclosures 540 mayeliminate the need to reposition the gas delivery assembly 502 for eachcycle of the main turret 108 to account for the decrease in length ofthe glass tube 102. However, as the length of the glass tube 102decreases, the volume flow rate of gas from the manifold 560 to theenclosure 540 that may be required to counteract the chimney effect inthe glass tube 102 may increase. Thus, in some embodiments, the valveactuator 510 may be operable to progressively increase the open positionof the valve 508 to increase the volume flow rate of gas during the gaspulse as the length of the glass tube 102 decreases. Alternatively, inother embodiments, the valve actuator 510 may be operable to actuate toan open position sufficient to provide the required volumetric flow rateof gas at the shortest length of the glass tube 102.

The valve actuator 510 may maintain the valve 508 in an open positionfor a discrete duration of time to produce a gas pulse through the glasstube 102. The valve 508 may then be fully closed to end the gas pulse.In alternative embodiments, the valve 508 may be operable to deliver agas pulse to the enclosure 540 by transitioning from a low gas flowposition to a greater gas flow position. In these embodiments, the lowgas flow position may provide a constant flow of gas to the enclosure540 to maintain a slight positive pressure in the enclosure 540. Whenthe gas pulse is initiated, the valve 508 may be opened further toincrease the flow rate of gas into the enclosure 540 for the duration ofthe pulse to generate the gas pulse. The valve 508 may then be partiallyclosed back to the low flow position to end the gas pulse. In someembodiments, the pulse duration may be less than the total cycle time ofthe converter. The total cycle time, as used herein, refers to the totaltime required to move a single glass tube 102 through the processingstations 106 of the converter 100, not including the secondaryprocessing stations. Alternatively, in other embodiments, the pulseduration may be less than the dwell time of the converter 100. In stillother embodiments, the pulse duration may be less than the index time ofthe converter 100. In still other embodiments, the pulse duration may beless than the sum of the index time and the dwell time of the converter.

Although described in the context of the piercing station 212, it isunderstood that the gas flow system 500 a may operate to deliver a gaspulse to the enclosure 540 to evacuate the internal volume of the glasstube 102 at one or more of the other processing stations 106, such asthe separating station 206 or one of the forming stations 204.Alternatively, the gas flow system 500 a may be configured to deliver agas pulse to the enclosure 540 sufficient to open the meniscus 350 ofthe glass tube 102 at the piercing station 212 or the separating station206. For example, when the glass tube 102 is indexed into position atthe piercing station 212, the gas flow system 500 a may be configured todeliver gas flow to the enclosure 540 enclosing the glass tube 102 atthe piercing station 212. The gas flow may be sufficient to open themeniscus 350. Using the gas flow system 500 a to pierce the meniscus 350may allow for elimination of the piercing burner 352 from the piercingstation 212.

In some embodiments, the gas flow system 500 a may be configured todeliver the gas pulse to the enclosure 540 at the separating station 206to open the meniscus 350 immediately following separation of the article103 from the glass tube 102. In these embodiments, the valve actuator510 of the gas delivery assembly 502 may operate to open the valve 508immediately following separation of the article 103 from the glass tube102 to open the meniscus 350 before the end of the dwell time of theglass tube 102 in the separating station 206. By piercing the meniscus350 in the separating station 206 with the gas delivery assembly 502,the piercing station 212 positioned downstream of the separating station206 may be eliminated from the converter 100 or reconfigured into adifferent type of processing station, such as a heating station 202,forming station 204, cooling station 210, measuring station 218, orother processing station 106. Eliminating the piercing burner 352 mayresult in substantial improvement in SHR performance of glass articles103 produced from the glass tube 102.

When the gas flow system 500 a is employed to pierce/open the meniscus350 of the glass tube 102 at the piercing station 212 or the separatingstation 206, the volume flow rate of gas may be sufficient to open themeniscus 350 of the glass tube 102. However, if the volume flow rate ofgas through the glass tube 102 becomes too great, the gas flow mayresult in destructive piercing of the meniscus 350, which may separatedroplets of molten glass from the proximal end 150 of the glass tube102. As previously described, the volume flow rate of gas that may berequired during the gas pulse to pierce the meniscus 350 of the glasstube 102 may increase as the glass tube 102 decreases in length throughmultiple passes through the processing stations 106 of the converter100.

Referring to FIGS. 1, 2, and 6, when the glass tube 102 is fullyconsumed, a new glass tube 102 may be loaded into the holder 130 at thetube loading station 214 (FIG. 2). To accommodate loading the glass tube102 into the holder 130, the cap 542 may be disengaged from the distalend 552 of the enclosure 540 and pivoted away from the distal end 552 toallow access to the holder 130. Once the new glass tube 102 is loadedinto the holder 130, the cap 542 may be engaged with the distal end 552of the enclosure 540 to seal the enclosure 540. The cap 542 may bemanually or automatically engaged and disengaged with the distal end 552of the enclosure 540 during tube loading in the tube loading station214.

In an alternative embodiment, the gas flow system 500 a may include asingle gas delivery assembly 502 having the enclosure 540. The singlegas delivery assembly 502 may be positioned at a specific processingstation 106, such as the piercing station 212, the separating station206, one of the heating stations 202, or one of the forming stations204. During operation, the enclosure 540 may be engaged with the holder130 to enclose the glass tube 102 secured in the holder 130 when theholder 130 is indexed into the processing station 106. The gas pulse maybe applied to the glass tube 102 by the gas delivery assembly 502through the enclosure 540 enclosing the glass tube 102. After the gaspulse, the enclosure 540 may be disengaged from the holder 130 andremoved from the processing station 106.

Referring to FIGS. 9A-15B, additional systems and methods disclosedherein may reduce or eliminate formation of deposits on the interiorsurface 146 of the glass tube 102 by introducing a negative pressure(e.g., a negative pressure pulse or a continuous suction) to theproximal end 150 of the glass tube 102 to produce a flow of gas and/orvapors through the glass tube 102 from the distal end 152 to theproximal end 150 (i.e., the −Z direction of the coordinate axis of FIG.9A). As used in this disclosure, the term “negative pressure” refers toa localized pressure that is less than ambient pressure, therebyproducing a suction force that induces a flow of gas towards the sourceof the negative pressure. Producing a flow of gas through the glass tube102 towards the proximal end 150 of the glass tube 102 by application ofa negative pressure to the proximal end 150 of the glass tube 102 maycounteract the chimney effect caused by heating the gases inside theglass tube 102 and may reduce or prevent vaporized volatile constituentsfrom traveling upward (i.e., in the +Z direction of the coordinate axisof FIG. 9A) through the glass tube 102 and condensing on the interiorsurface 146 of the glass tube 102. Additionally or alternatively, inother embodiments, the systems and methods disclosed herein may reduceor eliminate the formation of deposits on the interior surface 146 ofthe glass tube 102 by using the negative pressure (i.e., suction) toopen the meniscus 350, thereby eliminating the piercing burner 352 atthe piercing station 212.

Referring to FIGS. 9A, 9B, 10, 11, and 12, the converter 100 may includea gas flow system operable to produce a negative pressure at theproximal end 150 of the glass tube 102. In some embodiments, the gasflow system may be a suction system 600 positionable proximate to theproximal end 150 of the glass tube 102 when the glass tube 102 ispositioned in one of the processing stations 106 of the converter 100 orwhen the glass tube 102 is indexed between two processing stations 106.The suction system 600 may be operable to produce a negative pressure atthe proximal end 150 of the glass tube 102 to produce a flow of gasand/or vapors in the internal volume of the glass tube from the distalend 152 to the proximal end 150 of the glass tube 102 (e.g., the flow ofgas may be vertically downward in the −Z direction of the coordinateaxis in FIG. 9A). In some embodiments, the suction system 600 may bepositioned at a specific processing station 106, such as the piercingstation 212, the separating station 206, one of the heating stations202, one of the forming stations 204, or other processing stations 106.Alternatively, in other embodiments, the suction system 600 may bepositioned between two of the processing stations 106 to produce thenegative pressure at the proximal end 150 of the glass tube 102 when theglass tube 102 is indexed between the two processing stations 106. Forexample, the suction system 600 may be positioned between the separatingstation 206 and the piercing station 212 of the converter and/or betweenthe piercing station 212 and a heating station 202 or other processingstation 106 downstream of the piercing station 212.

In some embodiments, the suction system 600 may reduce the SHR of theglass articles 103 produced from the glass tube 102 by evacuating thegases and/or vapors from the internal volume of the glass tube 102. Inparticular, the negative pressure produced by the suction system 600through the suction tube 602 positioned close to the proximal end 150 ofthe glass tube 102 may be sufficient to overcome the chimney effect inthe internal volume of the glass tube 102 and cause the gases and/orvapors to flow towards the proximal end 150 of the glass tube 102 (i.e.,in the −Z direction of the coordinate axis of FIG. 9A) and out of theglass tube 102. Removing the gases and vapors from the internal volumeof the glass tube 102 may reduce or prevent vaporized volatileconstituents of the glass from condensing on the interior surface 146 ofthe glass tube 102, thereby reducing the SHR of the glass tube 102 andthe glass articles 103 made therefrom.

In other embodiments, the negative pressure produced by the suctionsystem 600 may be utilized to pierce the meniscus 350 of the glass tube102 formed during separation of the glass article 103 from the glasstube 102 in the separating station 206. Using the suction system 600 topierce the meniscus 350 may enable elimination of the piercing burner352 in the piercing station 212, which may further reduce the SHR ofglass articles 103 made from the glass tube 102 and may enable thepiercing station 212 to be reconfigured into another type of processingstation 106. Additionally, in some embodiments, using the suction system600 to open the meniscus 350 may enable elimination of the piercingstation 212 altogether, which may increase the efficiency of theconverter 100 by enabling faster converting and increased throughput.

The suction system 600 may also allow for the reduction of SHR of theglass tube 102 without having to adjust for the progressive shorteningof the glass tube 102 as the glass tube 102 cycles multiple timesthrough the processing stations 106 of the converter 100. The suctionsystem 600 is positioned at the proximal end 150 of the glass tube 102,which does not change positions as the glass tube 102 is consumedthrough multiple passes of the glass tube 102 through the processingstations 106.

Referring to FIGS. 9A and 9B, the suction system 600 may include asuction tube 602 and a vacuum generator 604 fluidly coupled to thesuction tube 602 by a conduit 606. The suction system 600 may optionallyinclude a vacuum manifold 607 fluidly coupling the vacuum generator 604to the conduit 606. In some embodiments, the suction system 600 mayinclude a plurality of suction tubes 602 disposed at different positionson the converter 100, such as at or between combinations of heatingstations 202, forming stations 204, separating stations 206, piercingstations 212, or other processing stations 106. In these embodiments,the optional vacuum manifold 607 may enable the vacuum generator 604 tosupply vacuum to the plurality of suction tubes 602 simultaneously.

In some embodiments, the suction system 600 may optionally include acontrol valve 614 to control an amount of negative pressure applied bythe suction tube 602 to the proximal end 150 of the glass tube 102. Asused herein, a “control valve” refers to a combination of a valve and anactuator operable to control the position of the valve (e.g., thecombination of valve 508 and actuator 510 described relative to FIG. 5may be considered a control valve), thereby controlling the flow throughthe valve. The control valve 614 may also control the duration of thenegative pressure applied by the suction tube 602. For example, thecontrol valve 614 may be operated to open and close to deliver anegative pressure pulse (i.e., a negative pressure applied for adiscrete period of time) to the proximal end 150 of the glass tube 102.The control valve 614 may include one or more of a pneumatic actuator,electric actuator, hydraulic actuator, electromagnetic actuator, orother type of actuator. In some embodiments, the control valve 614 mayinclude a solenoid.

The suction tube 602 may include a suction inlet 608 (FIG. 9B) disposedin a proximal end 610 of the suction tube 602. As used in relation tothe suction tube 602, the proximal end 610 is the end of the suctiontube 602 oriented towards the proximal end 150 of the glass tube 102. Adistal end 612 of the suction tube 602 may be coupled to the conduit606. The distal end 612 of the suction tube 602 refers to the end of thesuction tube 602 oriented away from the proximal end 150 of the glasstube 102. The suction tube 602 may be generally cylindrical in shapewith a cross-sectional shape that may be circular, oval, square,rectangular, polygonal, or any other convenient shape. Although thesuction tube 602 is described herein as being a structure separate fromthe conduit 606, it is understood that the suction tube 602 may also bean end portion of the conduit 606 such that the suction tube 602 and theconduit 606 form a unitary structure.

The suction tube 602 may be oriented parallel to the glass tube 102 withthe proximal end 610 of the suction tube 602 vertically below (i.e., inthe −Z direction of the coordinate axis of FIG. 9A) and facing towardsthe proximal end 150 of the glass tube 102 so that the suction inlet 608of the suction tube 602 at least partially overlaps with the opening inthe proximal end 150 of the glass tube 102 when viewed in the +/−Zdirection of the coordinate axis of FIG. 9A. In some embodiments, thesuction tube 602 may be centered on the axis of rotation D of the glasstube 102 so that the suction tube 602 is vertically aligned (i.e., inthe +/−Z direction of the coordinate axis of FIG. 9A) with the glasstube 102 and the suction inlet 608 is centered below the opening in theproximal end 150 of the glass tube 102.

The suction tube 602 may be positioned with the proximal end 610 of thesuction tube 602 spaced apart from the proximal end 150 of the glasstube 102 by a distance G2 in the +/−Z direction of the coordinate axisof FIG. 9A. In some embodiments, the distance G2 may be small enough toproduce a negative pressure sufficient to overcome the chimney effect inthe internal volume of the glass tube 102. In other embodiments, thedistance G2 may be small enough to produce a negative pressuresufficient to pierce the meniscus 350 formed over the proximal end 150of the glass tube 102 in the separating station 206. The distance G2 maybe decreased to reduce the amount of vacuum required to overcome thechimney effect in the internal volume of the glass tube 102 and producethe flow of gas and/or vapors towards the proximal end 150 of the glasstube 102 and/or pierce the meniscus 350 formed over the proximal end 150of the glass tube 102.

However, the proximal end 150 of the glass tube 102 may exhibitdimensional variability from glass tube to glass tube, and positioningthe suction tube 602 too close to the proximal end 150 of the glass tube102 may result in contact of the glass tube 102 with the suction tube602 during indexing of the glass tube 102 into the processing station106 or between processing stations 106. Additionally, when the suctiontube 602 is positioned at the piercing station 212, separating station206, or one of the heating stations 202, positioning the suction tube602 too close to the glass tube 102, may affect the performance of theburner (e.g., the burner 302, the separating burner 348, or the piercingburner 352). In particular, producing the negative pressure in closeproximity to the burner at the heating station 202, separating station206, or piercing station 212 may disrupt the flame by diverting theflame away from the glass tube 102 towards the suction tube 602.Furthermore, positioning the proximal end 610 of the suction tube 602too close to the glass tube 102 may reduce or eliminate the amount ofroom temperature air drawn into the suction tube 602, which may lead todamage to the suction tube 602, conduit 606, vacuum manifold 607, and/orthe vacuum generator 604. For example, heated gases and vapors from theinternal volume of the glass tube 102 as well as room temperature airmay be drawn into the suction tube 602. The room temperature air fromoutside the glass tube 102 mixes with the heated gases and vapors drawnfrom inside the glass tube 102 and cools the heated gases and vapors.The heated gases and vapors from the internal volume of the glass tube102 may reach temperatures greater than 1000° C., 1200° C., or even ashigh as 1500° C. Without room temperature air to mix with and cool thesegases and vapors, drawing these heated gases and vapors into the suctionsystem 600 through the suction tube 602 may cause thermal stress to thesuction system 600, which may result in damage to the suction tube 602,conduit 606, vacuum manifold 607, control valve 614, and/or the vacuumgenerator 604.

Referring to FIG. 9A, in some embodiments, the distance G2 between thesuction tube 602 and the glass tube 102 may be less than or equal to 25millimeters (mm). For example, in some embodiments, the distance G2between the suction tube 602 and the glass tube 102 may be less than orequal to 20 mm, less than or equal to 15 mm, less than or equal to 10 mmor less than or equal to 5 mm. In some embodiments, the distance G2between the suction tube 602 and the glass tube 102 may be influenced bythe inner diameter ID (FIG. 4) of the glass tube 102, the process speed,the converter setup, and/or the type of glass.

As previously described, positioning the suction tube 602 close to theproximal end 150 of the glass tube 102 may cause the suction tube 602 tocontact gases and/or vapors having temperatures in excess of 1000° C.,or even in excess of 1200° C. or 1500° C. In some embodiments, thesuction tube 602 may be constructed of heat resistant materials, such asa metals, ceramics, other refractory materials, or combinations thereof,to minimize damage to the suction tube 602 caused by the heated gasesand vapors. For example, the suction tube 602 may be made from one ormore of quartz, fused silica, alumina, Inconel, or combinations ofthese. The conduit 606 and/or the vacuum manifold 607 may also be madefrom heat resistant materials such as metal (e.g., steel, aluminum,Inconel, or other metal or metal alloy), ceramics, other refractorymaterials, heat resistant polymers, other heat resistant materials, orcombinations thereof.

The vacuum generator 604 may be any suitable device for producing avacuum or suction at the proximal end 610 of the suction tube 602. Insome embodiments, the vacuum generator 604 may be capable of producing anegative pressure at the proximal end 610 of the suction tube 602sufficient to evacuate the gases from the internal volume of the glasstube 102 and/or pierce the meniscus 350 of the glass tube 102. Examplesof vacuum generators may include, but are not limited, vacuum pumps,Venturi devices (e.g., vacuum ejectors), compressed air vacuumgenerators, vacuum compressors, fans, other apparatus capable ofproducing sufficient negative pressure, or combinations of these.

In some embodiments, the conduit 606 may be a rigid conduit, such as aconduit made from metals (e.g., steel, aluminum, Inconel, or other metalor metal alloy), glass, rigid heat resistant polymers, ceramics, orother rigid materials. Alternatively, in other embodiments, the conduit606 may be a flexible conduit, such as a rubber hose, flexible plasticconduit, or flexible metal hose. Using a flexible conduit for theconduit 606 may enable movement of the suction tube 602 relative to thevacuum generator 604 and/or the vacuum manifold 607 as describedsubsequently in this disclosure. In some embodiments, the conduit 606may be coupled to the suction tube 602 with a swivel connector (notshown) to enable the suction tube 602 to rotate slightly relative to theconduit 606.

FIGS. 9A and 9B illustrate the suction system 600 positioned between thepiercing station 212 and a heating station 202 downstream of thepiercing station 212 to produce the negative pressure as the glass tube102 is indexed between the piercing station 212 and the heating station202. Although depicted as being positioned between the piercing station212 and the heating station 202, it is understood that the suctionsystem 600 could be positioned between the separating station 206 andthe piercing station 212 or between any two other processing stations106 of the converter 100.

The suction system 600 may include a translation system 620 operable tomove the suction tube 602 between the piercing station 212 and theheating station 202 to maintain the suction tube 602 aligned with theglass tube 102 as the glass tube 102 is indexed from the piercingstation 212 to the heating station 202. In some embodiments, thetranslation system 620 may include a track 622 and a suction tubecarriage 624 engaged with the track 622 and translatable along the track622. The track 622 may be shaped to follow the path of the glass tube102 as it is indexed between the two processing stations 106. Forexample, in some embodiments, the track 622 may be arcuate in shape tofollow the arcuate path of the glass tube 102 indexed through processingstations 106 arranged in a circular pattern. Alternatively, in otherembodiments, the converter 100 may have a linear arrangement ofprocessing stations 106, and the track 622 may be linear. Other shapesfor the track 622 are contemplated depending on the spatial arrangementof the processing stations 106 of the converter 100. The suction tube602 may be coupled to the suction tube carriage 624 so that when thesuction tube 602 is positioned underneath the glass tube 102, theproximal end 610 of the suction tube 602 is spaced apart from theproximal end 150 of the glass tube 102 by the distance G2 previouslydescribed. Various devices may be utilized to translate the suction tubecarriage 624 along the track 622. Examples of these devices may include,but are not limited to, servo motors, hydraulic cylinders, or otherdevices capable of moving the suction tube carriage 624 along the track622.

In operation, at the end of the dwell time of the glass tube 102 in thepiercing station 212, the translation system 620 may position thesuction tube 602 at an end of the track 622 nearest to the piercingstation 212. When the dwell time concludes, the glass tube 102 may beindexed from the piercing station 212 to the heating station 202immediately downstream from the piercing station 212 (e.g., in thedirection of rotation of the main turret 108). As the glass tube 102moves out of the piercing station 212, the translation system 620 mayposition the suction tube 602 under the proximal end 150 of the glasstube 102 (i.e., in the −Z direction of the coordinate axis of FIG. 9A)and move the suction tube 602 in concert with the glass tube 102 tomaintain the suction tube 602 in alignment with and under the glass tube102 until the glass tube 102 reaches the heating station 202. Whilemoving the suction tube 602 along under the glass tube 102, the suctiontube 602 may produce a negative pressure at the proximal end 150 of theglass tube 102, which may overcome the chimney effect in the internalvolume of the glass tube 102 and cause the heated gases and vapors inthe internal volume of the glass tube 102, including volatileconstituents vaporized in the piercing station 212, to flow downward(i.e., −Z direction of the coordinate axis of FIG. 9A) through the glasstube 102 and out through the proximal end 150 of the glass tube 102.Producing the flow of heated gases and vapors downward through the glasstube 102 may reduce or prevent condensation of the volatile constituentson the interior surface 146 of the glass tube 102. When the suctionsystem 600 is positioned between the separating station 206 and thepiercing station 212, the suction from the suction tube 602 may besufficient to pierce the meniscus 350 formed at the proximal end 150 ofthe glass tube 102 in the separating station 206.

Referring to FIG. 9A, the control valve 614 of the suction system 600may operate to open and close to deliver a negative pressure pulse whilethe suction tube 602 is positioned underneath the glass tube 102. Forexample, in some embodiments, the control valve 614 may open when thesuction tube 602 is positioned under the glass tube 102 at theseparating station 206 end of the track 622 and close when the suctiontube 602 reaches the piercing station 212 end of the track 622.Alternatively, in other embodiments, the control valve 614 may beoperated to open for a duration shorter than a time required to move thesuction tube 602 along the entire track 622. At the end of the indextime, when the glass tube 102 is in position in the subsequentprocessing station (i.e., heating station 202 of FIGS. 9A and 9B), thetranslation system 620 may move the suction tube 602 back along thetrack 622 to the upstream processing station 106 (i.e., piercing station212 in FIGS. 9A and 9B) to position the suction tube 602 for indexingthe next glass tube 102 between processing stations 106.

Although the translation system 620 is described as including the track622 and the suction tube carriage 624, the translation system 620 mayalso include an arm that pivots about a pivot point or other mechanical,electromechanical, or magnetic device to maintain the suction tube 602aligned with the glass tube 102 during indexing of the glass tube 102.

Referring to FIG. 10, in an alternative embodiment, the suction system600 may be positioned at a specific processing station 106, such as thepiercing station 212 shown in FIG. 10, and the translation system 620may be operable to move the suction tube 602 into and out of positionunder the proximal end 150 of the glass tube 102 during the dwell timeof the converter 100, when the glass tube 102 is positioned in thepiercing station 212. As previously described, the translation system620 may include the track 622 and the suction tube carriage 624 movablealong the track 622 to move the suction tube 602 into and out ofposition beneath the glass tube 102. The suction tube 602 may be coupledto the suction tube carriage 624 so that when the suction tube 602 ispositioned underneath the glass tube 102, the proximal end 610 of thesuction tube 602 is spaced apart from the proximal end 150 of the glasstube 102 by the distance G2 previously described.

The translation system 620 may also include a suction tube actuator 625to move the suction tube carriage 624 along the track 622 to index thesuction tube 602 into and out of position beneath the proximal end 150of the glass tube 102. The translation system 620 may also include aburner carriage 626 coupled to the piercing burner 352, or other burneror forming tool, and movable along the track 622. The translation system620 may include a burner actuator 628 to move the burner carriage 626along the track 622 to index the piercing burner 352 into and out ofposition in the piercing station 212. The suction tube actuator 625 andburner actuator 628 may be any type of actuator capable of translatingthe suction tube carriage 624 and burner carriage 626, respectively,along the track 622. Examples of actuators that may be suitable for thesuction tube actuator 625, burner actuator 628, or both may include, butare not limited to, pneumatic actuators, electric actuators, hydraulicactuators, magnetic actuators, servo motors, gear systems, or otheractuators.

In operation, the piercing burner 352 may be indexed into position inthe piercing station 212 for piercing the meniscus 350 of the glass tube102 when the glass tube 102 is indexed in the piercing station 212. Oncethe piercing burner 352 pierces the meniscus 350, the burner actuator628 may be operated to move the piercing burner 352 out of position inthe piercing station 212, and the suction tube actuator 625 may beoperated to move the suction tube 602 into position underneath theproximal end 150 of the glass tube 102 and into alignment with the glasstube 102. The suction tube 602 may produce a negative pressure at theproximal end 150 of the glass tube 102 to draw heated gases and vaporsdownward (i.e., the −Z direction of the coordinate axis of FIG. 10)through the internal volume of the glass tube 102 and out of theproximal end 150 of the glass tube 102. In some embodiments, the controlvalve 614 may operate to open and close the suction tube 602 to delivera negative pressure pulse to the proximal end 150 of the glass tube 102when the suction tube 602 is in position beneath the glass tube 102. Forexample, the control valve 614 may be operated to open when the suctiontube 602 is first positioned beneath the glass tube 102 and close at theend of the dwell time. Alternatively, the control valve 614 may beoperated to open when the suction tube 602 is positioned beneath theglass tube 102 and close before the end of the dwell time or after theend of the dwell time. At the end of the dwell time, the converter 100indexes the glass tube 102 to the next processing station 106. Thetranslation system 620 then may operate to move the suction tube 602 outof position in the piercing station 212 and move the piercing burner 352back into position in the piercing station 212 to pierce the next glasstube 102 indexed into the piercing station 212.

Alternatively, in some embodiments, the suction tube actuator 625 may beoperable to translate the suction tube 602 vertically (i.e., in the +/−Zdirection of the coordinate axis of FIG. 10) into and out of positionproximate to the proximal end 150 of the glass tube 102.

Although the suction system 600 is depicted in FIG. 10 as beingpositioned at the piercing station 212 of the converter 100, it isunderstood that the suction system 600 may be positioned at any of theother processing stations 106 of the converter 100. For example, thesuction system 600 may be positioned at the separating station 206 ofthe converter 100, and the translation system 620 may be operable tomove the separating burner 348 and the suction tube 602 into and out ofposition in the separating station 206. The suction system 600 may alsobe positioned at one of the heating stations 202, one of the formingstations 204, or one of the other processing stations 106 of theconverter 100.

Referring to FIG. 11, the suction tube 602 may be coupled to thepiercing station 212 or other processing station 106 at a fixed positionrelative to the base 104 of the converter 100 so that the proximal end610 of the suction tube 602 is spaced apart from the proximal end 150 ofthe glass tube 102 by the distance G2 when the glass tube 102 is indexedinto the piercing station 212. In some embodiments, the suction tube 602may be mounted in a fixed position at an angle α relative to thecenterline of the glass tube 102 (i.e., axis D), as depicted in FIG. 11.In some embodiments, the angle α may be greater than zero and less than90°. Alternatively, in other embodiments, the suction tube 602 may beoriented substantially parallel to axis D and positioned with thecenterline of the suction tube 602 offset from axis D of the glass tube102. In these embodiments, when the suction tube 602 is substantiallyparallel to axis D, the angle α may be less or equal to than 5°, lessthan or equal to 3°, less than or equal to 1°, or about 0°. Althoughshown in FIG. 11 as being coupled to the piercing station 212 of theconverter 100, it is understood that the suction tube 602 may be coupledto any other processing station 106, such as one of the separatingstation 206, heating stations 202, or forming stations 204, for example.

In operation, the suction system 600 having the suction tube 602 coupledat a fixed position may be operable to provide a continuous negativepressure at the proximal end 610 of the suction tube 602. Alternatively,in some embodiments, the suction system 600 may be operable to produce anegative pressure pulse at the proximal end 150 of the glass tube 102.For example, the control valve 614 may operate to open for a discreteduration of time to deliver the negative pressure pulse and then mayclose to end the negative pressure pulse. In some embodiments, theduration of the negative pressure pulse may be less than the dwell timeof the converter 100. For example, in some embodiments, the suction tube602 may be positioned in the piercing station 212, and the suctionsystem 600 may be configured to open the control valve 614 to produce anegative pressure pulse to evacuate the heated gases and vapors from theinternal volume of the glass tube 102 after piercing the meniscus 350with the piercing burner 352.

Referring to FIGS. 21A and 21B, in some embodiments, the suction system600 may be used to pierce the meniscus 350 of the glass tube 102 in thepiercing station 212 instead of the piercing burner 352. In theseembodiments, the suction tube 602 may be coupled to the base 104 at thepiercing station 212 of the converter 100. The suction tube 602 may becoupled in a fixed position so that the suction tube 602 is alignedvertically (i.e., +/−Z direction of the coordinate axis of FIG. 11) withthe glass tube 102 (i.e., the centerline of the suction tube 602 isaligned with the axis D of the glass tube 102). The suction system 600may be operable to deliver a negative pressure pulse at the proximal end150 of the glass tube 102 sufficient to pierce the meniscus 350 formedat the proximal end 150 of the glass tube 102 in the separating station206.

As shown in FIGS. 21A and 21B, in some embodiments, the proximal end 610of the suction tube 602 may have an inner diameter IDS that is largerthan the width W of the glass tube 102. The suction system 600 mayinclude an actuator 616 operable to actuate the suction tube 602vertically upward (i.e., in the +Z direction of the coordinate axis ofFIG. 21A) towards the proximal end 150 of the glass tube 102. In someembodiments, the actuator 616 may move the suction tube 602 verticallyupward into a position in which the proximal end 610 of the suction tube602 surrounds the proximal end 150 of the glass tube 102. The actuator616 may be any type of mechanical, electromechanical, pneumatic,hydraulic, magnetic, or other type of actuator capable of indexing thesuction tube 602 upward towards the proximal end 350 of the glass tube102.

Referring to the embodiment in FIGS. 21A and 21B, in operation, the mainturret 108 may index the glass tube 102 into the piercing station 212.When the glass tube 102 is in position in the piercing station 212, theactuator 616 may actuate to move the suction tube 602 towards theproximal end 150 of the glass tube 102 so that the proximal end 610 ofthe suction tube 602 surrounds the proximal end 150 of the glass tube102, as shown in FIG. 21A. The suction tube 602 may apply the negativepressure to the meniscus 350 at the proximal end 150 of the glass tube102. The negative pressure may be sufficient to pierce the meniscus 350of the glass tube 102, as shown in FIG. 21B. In some embodiments, thesuction tube 602 may continue to produce the negative pressure afterpiercing the meniscus 350 to further evacuate gases and vapors from theinternal volume of the glass tube 102. The actuator 616 may then beactuated again to move the suction tube 602 vertically downward (i.e.,in the −Z direction of the coordinate axis of FIG. 21) away from theglass tube 102 to disengage the suction tube 602 from the proximal end150 of the glass tube 102. At the end of the dwell time of the converter100, the main turret 108 may then index the glass tube 102, which hasthe meniscus 350 pierced by the suction tube 602, from the piercingstation 212 to a downstream processing station 106.

In some embodiments, the suction system 600 may include a plurality ofsuction tubes 602, and each of the suction tubes 602 may be coupled toone of the holders 130 so that each of the suction tubes 602 may beindexed with the glass tube 102 through each of the processing stations106. In some embodiments, the vacuum manifold 607 may be positionedabove the main turret 108 and may be fluidly coupled to the vacuumgenerator 604 through a rotating union, such as the rotating union 560depicted in FIG. 8. In some embodiments, the suction system 600 may beconfigured to deliver suction to the proximal ends 150 of the glasstubes 102 continuously throughout the converting process. Alternatively,in other embodiments, the suction system 600 may be configured todeliver negative pressure pulses to the proximal ends 150 of the glasstubes 102 at one or more specific processing stations 106, such as oneof the heating stations 202, forming stations 204, separating station206, piercing station 212, or other processing station 106.

Referring to FIGS. 12A and 12B, in some embodiments, the piercingstation 212 of the converter 100 may include a piercing jet 630positioned to direct a gas flow across the meniscus 350 of the glasstube 102 to pierce the meniscus 350. The gas flow across the meniscus350 of the glass tube 102 may produce a vacuum or suction force againstthe meniscus 350 through the Bernoulli Effect. The suction force may besufficient to open the meniscus 350 of the glass tube 102 at thepiercing station 212. The velocity of the gas flow across the meniscus350 of the glass tube 102 may be influenced by the inner diameter ID ofthe glass tube 102, the process speed, the converter setup, and/or thetype of glass. The piercing jet 630 may be a gas jet, a burner, or anyother suitable type of nozzle capable of delivering a high-velocitystream of air across the meniscus 350 of the glass tube 102. Forexample, in some embodiments, the piercing jet 630 may be amulti-orifice planer burner. The piercing jet 630 may be fluidly coupledto one or more gas sources 632, such as fuel gas, oxygen, compressedair, nitrogen, inert gas, other gas or combinations of gases. Controlvalve 636 may be positioned between the gas source 632 and the piercingjet 630 to control operation of the piercing jet 630. For example, thecontrol valve 636 may be configured to open and close to deliver a burstof gas flow (i.e., a gas pulse) across the meniscus 350 at the proximalend 150 of the glass tube 102. The control valve 636 may include one ormore of a pneumatic actuator, electric actuator, hydraulic actuator,electromagnetic actuator, or other type of actuator. In someembodiments, the control valve 636 may include a solenoid.

As shown in FIGS. 12A and 12B, the piercing jet 630 may be coupled tothe base 104 of the converter 100 and may be oriented to produce a flowof gas generally perpendicular to the axis D of the glass tube 102 andparallel to the meniscus 350 of the glass tube 102 (i.e., generally inan X-Y plane of the coordinate axis of FIGS. 12A and 12B). Theproportions in FIG. 12B are exaggerated for purposes of illustration.Referring to FIG. 12B, the piercing jet 630 may be spaced radiallyoutward from the glass tube 102 so that the tip 634 of the piercing jet630 is radially spaced apart from the outer surface 140 of the glasstube 102 by a distance G3. The distance G3 between the tip 634 of thepiercing jet 630 and the outer surface 140 of the glass tube 102 may besmall enough to provide a gas stream having a gas velocity across thesurface of the meniscus 350 sufficient to create a suction force capableof opening the meniscus 350. However, if the distance G3 is too small,the tip 634 of the piercing jet 630 may contact the glass tube 102 whenthe glass tube 102 is indexed into and out of the piercing station 212.In some embodiments, the piercing jet 630 may be coupled to an actuator(not shown) that may be operable to move the piercing jet 630 into andout of position relative to the proximal end 150 of the glass tube 102.In some embodiments, the distance G3 between the tip 634 of the piercingjet 630 and the outer surface 140 of the glass tube 102 may be less thanor equal to 10 mm. However, in some embodiments, the distance G3 may beinfluenced by the inner diameter ID (FIG. 4) of the glass tube 102, theprocess speed, the converter setup, and/or the type of glass.

Referring to FIG. 12B, the piercing jet 630 may be vertically positioned(i.e., in the +/−Z direction of the coordinate axis of FIG. 12B) so thatthe gas flow from the piercing jet 630 flows across the meniscus 350 ofthe glass tube 102 to create a vacuum along the surface of the meniscus350 sufficient to open the meniscus 350. In some embodiments, thepiercing jet 630 may be positioned so that the center of the tip 634 ofthe piercing jet 630 is vertically aligned with the X-Y plane defined bythe meniscus 350 of the glass tube 102. Alternatively, the piercing jet630 may be vertically positioned lower (i.e., in the −Z direction of thecoordinate axis of FIG. 12B) than the proximal end 150 of the glass tube102 so that the tip 634 of the piercing jet 630 is spaced apart from theproximal end 150 of the glass tube 102 in the +/−Z direction of thecoordinate axis of FIG. 12B by a distance G4. The distance G4 may besmall enough to enable the gas flow from the piercing jet 630 to producesufficient suction force/vacuum against the meniscus 350 to open themeniscus 350. If the distance G4 is too great so that the piercing jet630 is vertically spaced too far from the meniscus 350 of the glass tube102, then the air flow from the piercing jet 630 may not be sufficientto create an amount of suction needed to pierce the meniscus 350. Thedistance G4 may be influenced by the inner diameter ID (FIG. 4) of theglass tube 102, the process speed, the converter setup, and/or the typeof glass.

Referring back to FIG. 12A, the piercing station 212 may also includethe suction tube 602 of the suction system 600 positioned verticallybelow the proximal end 150 of the glass tube 102. In some embodiments,the suction tube 602 may be vertically aligned (i.e., in the +/−Zdirection of the coordinate axis of FIG. 12A) with the axis D of theglass tube 102 to center the proximal end 610 of the suction tube 602directly below the proximal end 150 of the glass tube 102. In someembodiments, the proximal end 610 of the suction tube 602 may bevertically spaced apart from the proximal end 150 of the glass tube 102by the distance G2 previously described in this disclosure.Alternatively, in other embodiments, the suction tube 602 may be indexedupward towards the proximal end 150 of the glass tube 102 after thepiercing jet 630 pierces the meniscus 350.

Referring to FIG. 12A, in operation, the main turret 108 indexes theglass tube 102 from the separating station 206 to the piercing station212. Once the glass tube 102 is in position within the piercing station212, the control valve 636 may open to initiate gas flow across themeniscus 350 at the proximal end 150 of the glass tube 102 to open themeniscus 350. When the meniscus 350 has been opened, the control valve636 may partially or fully close to decrease or stop the gas flow acrossthe proximal end 150 of the glass tube 102. In some embodiments, thecontrol valve 636 may be maintained in the open or partially openposition to continue to apply suction at the proximal end 150 of theglass tube 102. In some embodiments, the gas pulse produced by thepiercing jet 630 and control valve 636 may have a duration that is lessthan the dwell time of the converter 100. In still other embodiments,the gas pulse may have a duration that is less than a sum of the dwelltime and the index time of the converter 100. The duration of the gaspulse produced by the piercing jet 630 may depend on the inner diameterID (FIG. 4) of the glass tube 102, the process speed, the convertersetup, and/or the type of glass. The control valve 614 of the suctionsystem 600 may then operate to deliver a negative pressure pulse throughthe suction tube 602 to the proximal end 150 of the glass tube 102. Insome embodiments, the suction tube 602 may be indexed into positionafter piercing and before the control valve 614 operates to deliver thegas pulse to the proximal end 150 of the glass tube 102. The negativepressure pulse may cause gases and vapors in the internal volume of theglass tube 102 to flow downward (i.e., in the −Z direction of thecoordinate axis of FIG. 12A) and out of the glass tube 102 through theproximal end 150 of the glass tube 102. Using the piercing jet 630 toopen the meniscus 350 of the glass tube 102 formed in the separatingstation 206 may reduce or prevent the deposition of vaporized volatileconstituents of the glass on the interior surface 146 of the glass tube102 by eliminating the piercing burner 352 in the piercing station 212.Integration of the suction system 600 with the piercing jet 630 toevacuate gases and vapors from the internal volume of the glass tube 102after piercing the meniscus 350 with the piercing jet 630 may furtherreduce deposition of vaporized volatile constituents of the glass on theinterior surface 146 of the glass tube 102. Reducing deposition ofvaporized volatile constituents of the glass on the interior surface 146of the glass tube 102 may reduce the SHR of the glass articles 103produced from the glass tube 102.

Referring to FIG. 12C, in an alternative embodiment, the piercing jet630 may be positioned at the separating station 206 of the converter100. The piercing jet 630 may be configured to deliver a gas pulseacross the meniscus 350 immediately after separation of the glassarticle 103 from the glass tube 102 and formation of the meniscus 350across the proximal end 150 of the glass tube 102. The piercing jet 630may be positioned and oriented relative to the proximal end 150 of theglass tube 102 as previously described in relation to FIGS. 12A and 12B.

Referring to FIG. 12C, in operation, the converter 100 indexes the glasstube 102 into the separating station 206. When the glass tube 102 is inposition in the separating station 206, the separating burner 348operates to heat the glass tube 102 and separate the glass article 103from the proximal end 150 of the glass tube 102. Once the glass article103 has been separated from the glass tube 102, the control valve 636may open to deliver a gas pulse through the piercing jet 630 and acrossthe meniscus 350 formed at the proximal end 150 of the glass tube 102during separation. The gas pulse may flow across the meniscus 350 andmay produce a suction force on the meniscus 350. The suction force onthe meniscus 350 may be sufficient to pierce the meniscus 350 to openthe proximal end 150 of the glass tube 102. As discussed hereinabove,incorporating the piercing jet 630 into the separating station 206 toopen the meniscus 350 in the separating station 206 may reduce thedeposition of vaporized volatile constituents of the glass on theinterior surface 146 of the glass tube 102 by eliminating the piercingburner 352. Eliminating the piercing burner 352 may enable the piercingstation 212 of the converter 100 to be reconfigured into a differenttype of processing station 106, such as a heating station 202 forexample. The ability to utilize the piercing station 212 for anadditional processing station 106 may improve the efficiency of theconverter 100, by reducing the processing time and increasing thethroughput.

Referring now to FIGS. 13A and 13B, the suction system 600 may include aring burner 640, a combustion gas source 642, and a control valve 646.The ring burner 640 may be configured to produce a downward (i.e., inthe −Z direction of the coordinate axis of FIG. 31A) conical flamearound the proximal end 150 of the glass tube 102. The downward-orientedconical flame may produce a downdraft that produces a negative pressureat the proximal end 150 of the glass tube 102. In some embodiments, thenegative pressure produced by the ring burner 640 may be sufficient toovercome the chimney effect in the internal volume of the glass tube 102to produce a flow of gases and/or vapors downward through the glass tube102 and out of the proximal end 150 of the glass tube 102. Alternativelyor additionally, in other embodiments, the negative pressure produced bythe ring burner 640 may be sufficient to pierce the meniscus 350 formedat the proximal end 150 of the glass tube 102 in the separating station206.

FIG. 13B illustrates a bottom view of an exemplary embodiment of thering burner 640 taken from the perspective of reference line 13B in FIG.13A. Referring to FIG. 13B, the ring burner 640 may include a ring orU-shaped burner manifold 648 having a plurality of jets 650 defined inan inner radial wall 652 of the burner manifold 648. In someembodiments, the jets 650 may comprise openings in the inner radial wall652. Alternatively, in other embodiments, the jets 650 may furtherinclude nozzles coupled to each of the openings in the inner radial wall652. The plurality of jets 650 may be oriented in a direction away fromthe proximal end 150 of the glass tube 102. For example, each of thejets 650 may be oriented slightly downward (i.e., in the −Z direction ofthe coordinate axis of FIG. 13). Referring to FIG. 13C, each jet 650 mayhave a centerline 656 that extends from the jet 650 downward and towardsthe axis D of the glass tube 102. The centerline 656 of the jet 650 mayintersect the axis D of the glass tube 102 to form an angle β betweenthe centerline 656 and the axis D. In some embodiments, the angle β maybe greater than 0° and less than 90°, such as from 10° to 80°, from 20°to 70°, or from 30° to 60°. In some embodiments, the jets 650 of thering burner 640 may produce a generally conical flame directedvertically downward in a direction away from the proximal end 150 of theglass tube 102.

As shown in FIG. 13B, the ring burner 640 may be positioned to becentered on the axis D of the glass tube 102 so that the ring burner 640surrounds the proximal end 150 of the glass tube 102. The burnermanifold 648 may have an inner diameter IDR that is larger than thewidth W of the glass tube 102 (i.e., the outer diameter of the glasstube 102) so that the inner radial wall 652 of the burner manifold 648is radially spaced apart from the outer surface 140 of the glass tube102 by a radial distance R, when viewed in bottom view (i.e., whenviewed in the +Z direction of the coordinate axis of FIG. 13A).

Referring back to FIG. 13A, the ring burner 640 may be positionedvertically (i.e., in the +/−Z direction of the coordinate axis of FIG.13A) below the proximal end 150 of the glass tube 102. The burnermanifold 648 of the ring burner 640 may be spaced apart from theproximal end 150 of the glass tube 102 by a distance F in the verticaldirection (i.e., the +/−Z direction of the coordinate axis of FIG. 13A).In some embodiments, the distance F may be sufficiently small to enablethe ring burner 640 to produce a negative pressure sufficient toovercome the chimney effect in the glass tube 102 and/or to open themeniscus 350 formed over the proximal end 150 of the glass tube 102.However, the distance F between the ring burner 640 and the proximal end150 of the glass tube 102 should not be so small that the ring burner640 contacts the proximal end 150 of the glass tube 102, which mayexhibit dimensional variability from tube to tube, when the glass tube102 is indexed between stations. In some embodiments, the distance F maybe less than or equal to 25 mm. For example, in some embodiments, thedistance F may be less than or equal to 20 mm, less than or equal to 15mm, less than or equal to 10 mm, or even less than or equal to 5 mm. Thedistance F may be influenced by the inner diameter ID of the glass tube102, the process speed, the converter setup, and/or the type of glass.

In some embodiments, the ring burner 640 may be translatable in thevertical direction (i.e., in the +/−Z direction of the coordinate axisof FIG. 13A) or in the horizontal direction (i.e., in the X-Y plane ofthe coordinate axis of FIG. 13A) relative to the proximal end 150 of theglass tube 102. For example, in some embodiments, the ring burner 640may be moved into and out of position in a processing station 106relative to the glass tube 102.

The combustion gas source 642 may be fluidly coupled to the ring burner640 by a conduit 654. The combustion gas source 642 may include one ormore of fuel gas, oxygen, compressed air, oxygen-enriched air, other gasor combinations of gases. Although FIG. 13A combustion gas source 642 asa single gas source, it is understood that combustion gas source 642 mayinclude multiple gas sources, such as the fuel gas, oxygen source, andcombustion air source (e.g., see the fuel gas supply 304, oxygen supply306, and combustion air supply 308 described in relation to burner 302in FIG. 3A). Referring to FIG. 13A, the control valve 646 may bepositioned between the gas source 642 and the ring burner 640 to controloperation of the ring burner 640. The control valve 646 may include oneor more of a pneumatic actuator, electric actuator, hydraulic actuator,electromagnetic actuator, or other type of actuator. In someembodiments, the control valve 646 may include a solenoid. Although FIG.13A depicts a single control valve 646, it is understood that multiplecontrol valves 646 may be utilized in the suction system 600 when thegas source 642 includes multiple gas sources. For example, when the gassource 642 includes a fuel gas source, an oxygen source, and acombustion air source, the suction system 600 may include multiplecontrol valves 646, one for each of the fuel gas, oxygen, and combustionair (e.g., similar to the fuel gas control valve 310, oxygen controlvalve 312, and air control valve 314 described for burner 302 in FIG.3A). Other configurations are contemplated. The position of the controlvalve 646 may be manipulated to transition the ring burner 640 between astandby mode and a suction mode (i.e., between a pilot flame mode andfull flame mode).

The suction system 600 having the ring burner 640 may be coupled to afixed position at a specific processing station 106, such as theseparating station 206, the piercing station 212, one of the heatingstations 202, one of the forming stations 204 or another processingstation 106. In some embodiments, the ring burner 640 of the suctionsystem 600 may be positioned in the piercing station 212 of theconverter 100. The ring burner 640 may produce sufficient negativepressure at the proximal end 150 of the glass tube 102 to pierce themeniscus 350 of the glass tube 102 in the piercing station 212. Usingthe ring burner 640 to pierce the meniscus 350 of the glass tube 102 mayeliminate the piercing burner 352 from the piercing station 212.Eliminating the piercing burner 352 may reduce the deposition ofvaporized volatile constituents on the interior surface 146 of the glasstube 102 by reducing the chimney effect in the internal volume of theglass tube 102. When used to pierce the meniscus 350, the ring burner640 may be operated after the meniscus 350 is pierced to continue togenerate the negative pressure to produce a flow of gases and vaporsdownward (i.e., the −Z direction of the coordinate axis of FIG. 13A)through the internal volume of the glass tube 102 and out of theproximal end 150 of the glass tube 102.

Alternatively, in other embodiments, the piercing station 212 mayinclude the piercing burner 352 for piercing the meniscus 350 of theglass tube 102. In operation of these embodiments, the main turret 108indexes the glass tube 102 into the piercing station 212. When the glasstube 102 is in position within the piercing station 212, the piercingburner 352 may operate to pierce the meniscus 350 of the glass tube 102.After the meniscus 350 is pierced, the piercing burner 352 may be shutoff and the ring burner 640 of the suction system 600 may be operable toproduce the negative pressure at the proximal end 150 of the glass tube102. The negative pressure may produce a flow of gases and vaporsdownward (i.e., towards the proximal end 150 of the glass tube 102 inthe −Z direction of the coordinate axis of FIG. 13A) through theinternal volume of the glass tube 102 and out of the proximal end 150 ofthe glass tube 102. Evacuating the gases and vapors from the internalvolume of the glass tube 102 with the ring burner 640 immediately afterpiercing the meniscus 350 of the glass tube 102 may reduce thedeposition of vaporized volatile constituents of the glass on theinterior surface 146 of the glass tube 102.

Referring now to FIGS. 14A and 14B, the suction system 600 may comprisean exhaust system 670 that may include at least one inlet vent 672fluidly coupled to an air handler 674 by a duct 676. The air handler 674may be capable of drawing air into the inlet vent 672 and through theduct 676. Drawing air in through the inlet vent 672 may produce alocalized negative pressure in the area of the proximal end 150 of theglass tube 102. This negative pressure may be sufficient to overcome thechimney effect produced by the piercing burner 352 in the piercingstation 212 or one of the burners 302 in one of the heating stations202. The negative pressure, by overcoming the chimney effect, mayproduce a flow of gases and vapors in the internal volume of the glasstube 102 towards the proximal end 150 of the glass tube 102 and out ofthe glass tube 102, thereby evacuating the gases and/or vapors from theinternal volume of the glass tube 102. As previously discussed,evacuating the gases and/or vapors may reduce or prevent condensation ofvaporized volatile constituents of the glass on the interior surface 146of the glass tube 102, thereby reducing the SHR of the glass tube 102and the glass articles 103 made therefrom.

Referring to FIGS. 14A and 14B, the inlet vent 672 may have an inletopening 678 that may be positioned a distance M from the outer surface140 of the glass tube 102 at the proximal end 150 of the glass tube 102.In some embodiments, the inlet vent 672 may be positioned between theprocessing station 106 and the main turret 108 and oriented so that theinlet opening 678 of the inlet vent 672 is spaced radially apart fromthe glass tube 102 in the processing station 106 by the distance M.Alternatively, in other embodiments (not shown), the inlet vent 672 maybe positioned directly below the proximal end 150 of the glass tube 102and oriented so that the inlet opening 678 faces vertically upward(i.e., in the +Z direction of the coordinate axis of FIGS. 14A and 14B).In these embodiments, the inlet vent 672 may be axially spaced apartfrom the proximal end 150 of the glass tube 102 by the distance M.

The distance M may be small enough to enable the exhaust system 670 togenerate a negative pressure at the proximal end 150 of the glass tube102 sufficient to overcome the chimney effect in the internal volume ofthe glass tube 102. However, if the distance M is too small, the inletvent 672 may contact the proximal end 150 of the glass tube 102 as theglass tube 102 is indexed into or out of the processing station 106 dueto slight dimensional variations in the glass tube 102 and/or theconverter 100. Additionally, if the distance M is too small, the inletvent 672 may interfere with the performance of the burners, such as thepiercing burner 352 of the piercing station 212 or the burners 302 ofone of the heating stations 202. In some embodiments, the distance M maybe less than less than or equal to 25 mm. For example, in someembodiments, the distance M may be less than or equal to 20 mm, lessthan or equal to 15 mm, less than or equal to 10 mm or less than orequal to 5 mm. In other embodiments, the distance M may be from 2 mm to25 mm, from 2 mm to 20 mm, from 2 mm to 15 mm, from 2 mm to 10 mm, from2 mm to 5 mm, from 5 mm to 25 mm, from 5 mm to 20 mm, from 5 mm to 15mm, or from 5 mm to 10 mm.

The air handler 674 may include, but is not limited to, one or more of ablower, fan, pump, vacuum pump, other vacuum device or air handlingapparatus, or combinations of these. The duct 676 coupling the airhandler 674 to the inlet vent 672 may include rigid duct, flexible duct,or a combination of both. Flexible duct may provide for adjustments tothe position of the inlet vent 672 relative to the proximal end 150 ofthe glass tube 102. Because of the proximity of the inlet vent 672 andduct 676 to the processing stations 106, in some embodiments, the inletvent 672 and the duct 676 may be constructed of heat resistant materialscapable of withstanding the temperatures of heated gases and vaporsgenerated in the vicinity of the glass tube 102 in the processingstations 106. Examples of heat resistant materials may include metals,ceramics, refractory materials, heat resistant plastics, other heatresistant materials, or combinations of these.

In some embodiments, the exhaust system 670 may optionally include adamper 680 positioned in the duct 676, between the duct 676 and the airhandler 674, or between the duct 676 and the inlet vent 672. The damper680 may be adjustable to control airflow through the exhaust system 670,thereby controlling the negative pressure generated by the exhaustsystem 670 at the proximal end 150 of the glass tube 102. The damper 680may include one or more of a pneumatic actuator, electric actuator,hydraulic actuator, electromagnetic actuator, or other type of actuator.In some embodiments, the damper 680 may include a solenoid.

Referring to FIGS. 14A and 14B, the inlet vent 672 may be positioned ata processing station 106, such as the separating station 206, thepiercing station 212, one of the heating stations 202, one of theforming stations 204, or combinations of these. In some embodiments, thesuction system 600 may include a plurality of vents 672 with each of thevents 672 positioned at one of the processing stations 106. Inoperation, the inlet vent 672 may be positioned next to or below theproximal end 150 of the glass tube 102 as previous described. The airhandler 674 may generate airflow through the duct 676 from the inletvent 672 towards the air handler 674. Air from the vicinity of theproximal end 150 of the glass tube 102 is drawn into the inlet vent 672by the flow of air through the duct 676, thereby producing a negativepressure in the vicinity of the proximal end 150 of the glass tube 102.The negative pressure may overcome the chimney effect and cause thegases and vapors inside the glass tube 102 to flow towards the proximalend 150 of the glass tube 102 and out of the glass tube 102.

Referring to FIGS. 15A and 15B, in some embodiments, the inlet vent 672may be positioned between processing stations 106, such as between theseparating station 206 and the piercing station 212 or between thepiercing station 212 and a downstream processing station 106, forexample. FIG. 15A depicts the inlet vent 672 positioned between thepiercing station 212 and the heating station 202 downstream of thepiercing station 212. The inlet vent 672 may be shaped to mirror thepath taken by the glass tube 102 when the glass tube 102 is indexedbetween the two processing stations 106. For example, in someembodiments, the inlet vent 672 may be elongated and curved to coincidewith an arcuate path of travel of the glass tube 102 as it is indexedbetween the processing stations 106. As shown in FIGS. 15A and 15B, theinlet vent 672 may be shaped like an elongated arcuate funnel with theopening 678 oriented vertically upward (i.e., in the +Z direction of thecoordinate axis of FIG. 15A) facing the proximal end 150 of the glasstube 102. Alternatively, in other embodiments, the converter 100 mayhave a linear shaped arrangement of processing stations 106, and theinlet vent 672 may be rectangular when viewed in top view to follow alinear path of the glass tube 102 between processing stations 106. Theinlet vent 672 may be vertically spaced apart (i.e., in the +/−Zdirection of the coordinate axis of FIG. 15A) from the proximal end 150of the glass tube 102 by the distance M previously described.

Referring to FIG. 15B, in operation, at the end of the dwell time, theconverter 100 may index the glass tube 102 from the piercing station 212to the heating station 202 downstream of the piercing station 212. Theexhaust system 670 may operate continuously to produce a continuousnegative pressure in the areas above the inlet vent 672. As the glasstube 102 passes out of the piercing station 212 during the index time,the proximal end 150 of the glass tube 102 may travel over and along theinlet vent 672 of the exhaust system 670, thereby subjecting theproximal end 150 of the glass tube 102 to the negative pressure abovethe inlet vent 672. As previously discussed, as the glass tube 102travels along the inlet vent 672, the negative pressure produced by theexhaust system 670 may overcome the chimney effect in the glass tube 102and cause the gases and vapors in the glass tube 102 to flow towards theproximal end 150 of the glass tube 102 and out of the glass tube 102. Asthe glass tube 102 enters the separating station 206 during the lastpart of the rotation, the glass tube 102 may pass beyond the inlet vent672 and out of the negative pressure region produced above the inletvent 672.

Referring to FIGS. 5-8, a method for producing an article 103 from aglass tube 102 having an inner surface 146 may include introducing theglass tube 102 to a converter 100 having a plurality of processingstations 106 comprising at least one heating station 202 and at leastone forming station 204 and heating the proximal end 150 of the glasstube 102 at the at least one heating station 202, wherein alkali isreleased from the glass tube 102 during the heating. The method furtherincludes forming at least one feature of the article 103 at the proximalend 150 of the glass tube 102 in the at least one forming station 204,separating the article 103 from the proximal end 150 of the glass tube102 at a separating station 206, and producing a flow of gas adjacent tothe proximal end 150 of the glass tube 102. The flow of gas is operableto remove at least a portion of the atmosphere in an interior of theglass tube 102. In some embodiments, the contamination of the innersurface 146 by the alkali released from the glass tube 102 is at leastreduced.

In some embodiments, producing the flow of gas adjacent to the proximalend 150 of the glass tube 102 may include producing a flow of gas fromthe distal end 152 towards the proximal end 150 of the glass tube 102.In some embodiments, separating the article 103 from the glass tube 102may include thermally separating the article 103 from the glass tube 102such that a meniscus 350 of glass is formed on the proximal end 150 ofthe glass tube 102 during thermal separation. In some embodiments,producing the flow of gas adjacent to the proximal end 150 the glasstube 102 may open the meniscus 350 of glass. In some embodiments,producing the flow of gas adjacent to the proximal end 150 of the glasstube 102 may include producing a positive flow of gas orthogonal to alongitudinal axis of the glass tube 102 adjacent to the proximal end 150of the glass tube 102. Alternatively or additionally, in someembodiments, producing the flow of gas adjacent to the proximal end 150of the glass tube 102 may include producing a positive flow of gasexternal to the glass tube 102 and at a non-zero angle with thelongitudinal axis of the glass tube 102.

In some embodiments, producing the flow of gas adjacent to the proximalend 150 of the glass tube 102 may include introducing a gas pulse intothe distal end 152 of the glass tube 102. In some of these embodiments,separating the article 103 from the glass tube 102 may include thermallyseparating the article 103 from the glass tube 102 and forming ameniscus 350 of glass across the proximal end 150 of the glass tube 102.The gas pulse may be sufficient to open the meniscus 350 of the glasstube 102. In some embodiments, the gas pulse may have a duration lessthan a sum of a dwell time or and an index time of the converter 100. Insome embodiments, the method may further include adjusting a flow rateor volume of the gas pulse in response to changes in a length of theglass tube 102.

In some embodiments, producing the flow of gas adjacent to the proximalend 150 of the glass tube 102 may include producing a negative pressureat the proximal end 150 of the glass tube 102. Producing the negativepressure at the proximal end 150 of the glass tube 102 may includeproducing a negative pressure pulse adjacent to the proximal end 150 ofthe glass tube 102. In some embodiments, the negative pressure pulse maybe sufficient to open the meniscus 350 formed at the proximal end 150 ofthe glass tube 102 during thermal separation. In some embodiments,producing the flow of gas adjacent to the proximal end 150 of the glasstube 102 may include producing the flow of gas radially across a surfaceof a meniscus 350 of glass formed on the glass tube during thermallyseparating the article 103 from the glass tube 102, wherein the flow ofgas produces a negative pressure sufficient to open the meniscus 350. Insome embodiments, the flow of gas adjacent to the proximal end 150 ofthe glass tube 102 may be produced when the glass tube 102 is positionedin at least one of the plurality of processing stations 106.Alternatively, in other embodiments, the method may further includeindexing the glass tube 102 between two of the plurality of processingstations 106 and the flow of gas adjacent to the proximal end 150 of theglass tube 102 may be produced while indexing the glass tube 102 betweenthe two of the plurality of processing stations 106.

Referring now to FIGS. 16A-20, embodiments of a gas flow system 900 andmethods for reducing and/or preventing the formation of deposits on theinterior surface 146 of the glass tube 102 using the gas flow system 900during the conversion process are disclosed. These systems and methodsmay reduce and/or prevent the formation of deposits of volatileconstituents of the glass on the interior surface 146 of the glass tube102 by introducing a flow of gas or gas pulse (i.e., a flow of gas for alimited duration) through the glass tube 102 to open the meniscus 350 ofglass formed at the proximal end 150 of the glass tube 102 in theseparating station 206 or in the piercing station 212. The gas flow orgas pulse delivered by the gas flow system 900 may be sufficient to openthe meniscus 350 instead of using the piercing burner 352. The gas pulseintroduced by the gas flow system 900 may pass through the glass tube102 from the distal end 152 to the proximal end 150 of the glass tube102 (i.e., the −Z direction of the coordinate axis of FIG. 16A). Thus,the gas flow system 900 may allow for elimination of the piercing burner352 and/or elimination of the piercing station 212 of the converter 100.Eliminating the piercing burner 352 from the converter 100 may reducethe chimney effect which may cause deposition of volatile constituentsof the glass on the interior surface 146 of the glass tube 102.Additionally, removing the piercing burner 352 may allow the piercingstation 212 to be converted to another type of processing station 106,such as a heating station 202 for example.

Referring to FIGS. 16A-16B, the converter 100 may include a gas flowsystem 900 operable to deliver a flow of gas or a gas pulse into thedistal end 152 of the glass tube 102, thereby producing a flow of gasthrough the glass tube 102 from the distal end 152 to the proximal end150. In some embodiments, the gas flow system 900 may be operable tointroduce a gas pulse through the glass tube 102 immediately followingseparation of the glass article 103 from the glass tube 102 in theseparating station 206. In some embodiments, the gas flow or gas pulsethrough the glass tube 102 may be sufficient to open the meniscus 350formed at the proximal end 150 of the glass tube 102 followingseparation of the glass article 103 from the glass tube 102 at theseparating station 206. In still other embodiments, the gas flow system900 may be operable to deliver a gas pulse through the glass tube 102 atother processing stations 106, such as heating stations 202 or formingstations 204 for example, to counteract the chimney effect in the glasstube 102 and reduce or prevent deposition of volatile constituents ofthe glass onto the interior surface 146 of the glass tube 102.

Referring to FIGS. 16A and 17, for each of the holder 130 positions ofthe converter 100, the gas flow system 900 may include a glass tubeconnector 902 engageable with the distal end 152 of the glass tube 102.In some embodiments, the glass tube connector 902 may be a stopper madefrom a resilient material, such as rubber for example. In someembodiments, the glass tube connector 902 may include one or more ofpolytetrafluoroethylene (Teflon™ marketed by Chemours), silicone, Viton,nitrile rubber (Buna N), other fluoropolymer, or combinations of these.In some embodiments, the glass tube connector 902 may be a resilientmaterial approved for contact with pharmaceutical compositions. In someembodiments, the glass tube connector 902 may be engageable with thedistal end 152 of the glass tube 102 through an interference fit withthe interior surface 146 of the glass tube 102. At least a portion ofthe glass tube connector 902 may be disposed inside the glass tube 102with a portion of an outer surface of the glass tube connector 902contacting the interior surface 146 of the glass tube 102 to produce agas-tight seal between the glass tube connector 902 and the interiorsurface 146 of the glass tube 102. Alternatively, the glass tubeconnector 902 may be a cap engageable with the outer surface of thedistal end 152 of the glass tube 102, such as by an interference fitbetween an inner surface of the cap and the outer surface 140 of theglass tube 102.

Referring to FIG. 17, the glass tube connector 902 may include a centralbore 914 extending longitudinally (i.e., in the +/−Z direction of thecoordinate axis of FIG. 17) through the glass tube connector 902. Aswivel connector 904 may be coupled to the glass tube connector 902 andcoupled to a flexible conduit 906. In some embodiments, a portion of theswivel connector 904 may be disposed within the central bore 914 of theglass tube connector 902. The swivel connector 904 may swivel or rotateto allow the glass tube connector 902 to rotate relative to the flexibleconduit 906, which may allow the glass tube connector 902 to rotate withthe glass tube 102 when the glass tube 102 is rotated by the holder 130in one or more processing stations 106.

Referring to FIG. 16A, each flexible conduit 906 may be coupled to avalve 908 to fluidly couple the valve 908 to the glass tube connector902 and the distal end 152 of the glass tube 102. The valve 908 may beany type of valve suitable for controlling the flow of gases. Examplesof valves suitable for valve 908 may include, but are not limited toball valves, gate valves, globe valves, butterfly valves, or other typesof valves. Each of the valves 908 may also be operatively coupled to avalve actuator 910 configured to open and close the valve 908 to controlthe flow of gas to the glass tube connector 902. The valve actuator 910may be a pneumatic actuator, an electronic actuator, a hydraulicactuator, an electromechanical actuator, an electromagnetic actuator, orother type of actuator. In some embodiments, the valve actuator 910 maybe a solenoid.

Referring to FIGS. 18 and 19, the valve 908 for each of the glass tubeconnectors 902 may be fluidly coupled to a manifold 920. In someembodiments, the manifold 920 may be mechanically coupled to the mainturret 108 for rotation with the main turret 108 during operation of theconverter 100. The manifold 920 may be fluidly coupled to the gas source504 through a gas supply conduit 922 and a rotating union 924. Althoughthe manifold 920 is depicted in FIGS. 18 and 19 as having a circularshape, the manifold 920 may have other shapes. For example, in someembodiments, the converter 100 may have a linear arrangement ofprocessing stations 106, and the manifold 920 may have a lineararrangement corresponding to the linear path of the glass tube 102 as itis indexed through the processing stations 106.

Referring to FIG. 19, in some embodiments, the gas flow system 900 mayinclude a flow meter 918. The flow meter 918 may be a mass flow meter, amass flow controller, or a volume flow meter. In some embodiments, theflow meter 918 may be disposed between the valve 908 and the manifold920. Alternatively, in other embodiments, the flow meter 918 may bepositioned downstream of the valve 908, such as between the valve 908and the glass tube connector 902. In still other embodiments, the flowmeter 918 may be positioned upstream of the manifold 920, such asbetween the manifold 920 and the gas source 504.

Referring back to FIGS. 18 and 19, the manifold 920 may include aplurality of distribution ports 921. Each distribution port 921 mayinclude a connector 923 which may be removably coupleable to one of theplurality of valves 908. Alternatively, in other embodiments, each ofthe valves 908 may be positioned between the connector 923 and thedistribution port 921 at one of the distribution ports 921. In theseembodiments, each connector 923 may be coupled directly to the one ofthe flexible conduits 906.

During operation of the gas flow system 900, gas may flow from the gassource 504 and into the manifold 920. The manifold 920 may distributethe gas flow to each of the distribution ports 921. Upon actuation ofthe valve actuator 910, the gas flows through the valve 908, theflexible conduit 906, and the glass tube connector 902, to deliver a gaspulse into the distal end 152 of the glass tube 102. The gas from thegas source 504 may include compressed air, nitrogen, inert gas, reactantgas, other gas or combination of gases. In some embodiments, the gas ofthe gas source may be an inert gas, such as argon, which may furtherreduce the probability of forming deposits on the interior surface 146of the glass tube 102.

In some embodiments, the gas pulse may have a pulse duration that may beless than the time required for the main turret 108 to cycle oncethrough all of the processing stations 106. Alternatively, in otherembodiments, the pulse duration may be less than the dwell time of theconverter 100. In still other embodiments, the pulse duration may beless than the index time of the converter 100. In still otherembodiments, the pulse duration may be less than the sum of the dwelltime and the index time of the converter. In some embodiments, the pulseduration may be less than a sum of the index time and the dwell time ofthe converter 100. The pulse duration may be influenced by the innerdiameter ID (FIG. 4) of the glass tube 102, the process speed, theconverter setup, and/or the glass type.

When a new glass tube 102 is loaded into one of the holders 130 of theconverter 100, the glass tube connector 902 from that holder positionmay be removed from the distal end 152 of the consumed glass tube 102,the new glass tube 102 may be loaded into the holder 130, and the glasstube connector 902 may be inserted into the distal end 152 of the newglass tube 102. In some embodiments, the glass tube connector 902 may beremoved from one glass tube and inserted into a new glass tube manuallyby an operator of the converter 100. In other embodiments, an insertiondevice 960 may be used to remove the glass tube connector 902 and insertthe glass tube connector 902 in the new glass tube. The insertion device960 may be a pneumatic, hydraulic, electromechanical, or electromagneticdevice capable of removing and inserting the glass tube connector 902into the distal end 152 of the glass tube 102. For example, theinsertion device 960 may be a robotic arm as illustrated in FIG. 18.Other types of insertion devices 960 are contemplated.

Referring to FIGS. 16A-16B, the gas flow system 900 may be utilized tointroduce the gas pulse into the glass tube 102 immediately afterseparation of the article 103 from the glass tube 102 in the separatingstation 206 to open the meniscus 350 immediately following separation.Referring to FIG. 16A, in the separating station 206, the separationburners 348 heat the separation region 346 of the glass tube 102 toseparate the article 103 from the glass tube 102. Referring to FIG. 16B,immediately after the article 103 is separated from the glass tube 102,the valve actuator 910 corresponding to the separating station 206 mayactivate to partially or fully open the valve 908 to allow the gas toflow from the gas source 504 through the valve 908 and into the distalend 152 of the glass tube 102 at the separating station 206. The gasflow through the glass tube 102 may be sufficient to open the meniscus350 formed over the proximal end 150 of the glass tube 102. In someembodiments, the valve actuator 910 may maintain the valve 908 in theopen or partially open position for a period of time following openingof the meniscus 350 to further evacuate vaporized volatile constituentsfrom the internal volume of the glass tube 102. At the expiration of theperiod of time, the valve actuator 910 may operate to close the valve908 to end the gas pulse into the distal end 152 of the glass tube 102.

In some embodiments, the gas flow system 900 may be configured todeliver a gas pulse to the distal end 152 of the glass tube 102 at oneor more processing stations 106 other than the separating station 206.For example, the gas flow system 900 may be configured to deliver a gaspulse to the distal end 152 of the glass tube 102 at one or more heatingstations 202, forming stations 204, cooling stations 210, otherprocessing stations 106, or combinations of processing stations.

In some embodiments, the gas pulse introduced to the distal end 152 ofthe glass tube 102 may have a volumetric flow rate of gas during the gaspulse sufficient to open the meniscus 350 of the glass tube 102 afterseparation of the glass article 103 from the glass tube 102. In still inother embodiments, the volumetric flow rate of gas during the gas pulsemay be sufficient to evacuate gases and vapors from the internal volumeof the glass tube 102. However, if the volumetric flow rate of gasduring the gas pulse is too high, undesired cooling of the glass tube102 may result. The volume flow rate of the gas during the gas pulse maybe influenced by the inner diameter ID (FIG. 4) of the glass tube 102,the process speed, the converter setup, and/or the glass type.

As each glass article 103 is separated from the glass tube 102 throughmultiple cycles of the glass tube 102 through the processing stations106 of the converter 100, the length of the glass tube 102 decreases,which reduces the internal volume of the glass tube 102. As the internalvolume of the glass tube 102 decreases, the volumetric flow rate or themass flow rate of gas sufficient to prevent formation of the meniscus350, to pierce the meniscus 350 after separation, or to evacuate vaporsfrom the internal volume of the glass tube 102 may also decrease.Similarly, as the internal volume of the glass tube 102 decreases, thepressure of the gas pulse sufficient to open the meniscus 350 afterseparation or to evacuate vapors from the internal volume of the glasstube 102 may also decrease. In some embodiments, operation of theconverter 100 with the gas flow system 900 may include modifying atleast one of the duration of the gas pulse, the pressure of the gaspulse, or the volume flow rate (or mass flow rate) of the gas pulse inresponse to a change in a length of the glass tube 102. In someembodiments, the volumetric flow rate and/or pressure of gas during thegas pulse may be decreased with each decrease in the length of the glasstube 102. The volume of the gas pulse introduced to the glass tube 102may be modified by changing the duration of time that the valve 908 isopen. The volume or mass flow rate of the gas pulse may also be changedby utilizing a mass flow controller or mass flow meter. Alternatively,in other embodiments, the volumetric flow rate and/or pressure of thegas during the gas pulse may be set to a volumetric flow rate sufficientto open the meniscus 350 after separation or to evacuate vapors from theinternal volume of the glass tube 102 for a new glass tube 102 having amaximum length prior to separation of a glass article 103 therefrom.

By opening the meniscus 350 in the separating station 206 immediatelyfollowing thermal separation of the article 103 from the glass tube 102,the gas flow system 900 may eliminate the piercing burner 352 from thepiercing station 212. Eliminating the piercing burner 352 from thepiercing station 212 may reduce the amount of vaporized volatileconstituents deposited on the interior surface 146 of the glass tube102, which may reduce the SHR of the glass article 103 made from theglass tube 102. The gas flow system 900 may also be utilized tointroduce a gas pulse into other processing stations 106, such asheating station 202 and forming station 204, to evacuate the internalvolume of the glass tube 102, which may further reduce or preventdeposits of vaporized volatile constituents on the interior surface 146of the glass tube 102. Further, eliminating the piercing burner 352 fromthe piercing station 212 may allow the piercing station 212 to bereconfigured into another type of processing station 106, such as aheating station 202 or a forming station 204. For example, the piercingstation 212 may be reconfigured into a forming station 204 to furtherbuild-up the thickness of the proximal end 150 of the glass tube 102prior to downstream forming stations 204. In some embodiments, thepiercing station 212 may be removed altogether to reduce the number ofprocessing stations 106 on the converter 100, thereby increasing theefficiency of the converter 100 by increasing the throughput.Additionally, the gas pulse may provide cooling to the interior surface140 of the glass tube 102 after separation or other heating or formingoperation. For example, the gas pulse may be continued after separationof the glass article 103 from the glass tube 102 for a duration of timeto provide cooling to the interior surface 140 of the glass tube 102,thereby decreasing the amount of time that the glass tube 102 is exposedto temperatures sufficient to vaporize volatile constituents of theglass.

As previously described in relation to FIGS. 18 and 19, the gas flowsystem 900 may include the valve 908 and the valve actuator 910 for eachof the glass tube connectors 902 corresponding to each of the holders130 of the converter 100. Alternatively, in some embodiments, the gasflow system 900 may include a single valve 908 a and a single actuator910 a operatively coupled to the valve, as illustrated in FIG. 20.Referring to FIG. 20, the gas flow system 900 may include a manifold 920a that has an inner ring 930 and an outer ring 940 positioned tosurround the inner ring 930 and rotatable relative to the inner ring930. The manifold 920 a of the gas flow system 900 is schematicallydepicted in FIG. 20 in an exploded view to better illustrate the innerring 930 and the outer ring 940. When installed, the inner ring 930 maybe positioned within the outer ring 940 so that an outer surface 936 ofthe inner ring 930 may be in slidable contact with an inner surface 946of the outer ring 940. The inner ring 930 may have gas supply channel932 extending from a central region 934 of the inner ring 930 to theouter surface 936 of the inner ring 930. The gas supply channel 932 maybe fluidly coupled to an inlet coupling 935. The inlet coupling 935 maybe in fluid communication with the single valve 908 a through the gassupply conduit 922. The inner ring 930 may be rigidly coupled to one ormore fixed supports 938 so that the inner ring 930 may remain stationaryduring operation of the converter 100 and does not rotate with the mainturret 108. The fixed support 938 may be coupled to a stationary objectsuch as a wall, ceiling, floor, or base of the converter, for example.

In some embodiments, the inner ring 930 may have a single gas supplychannel 932. The inner ring 930 may be oriented so that the single gassupply channel 932 may be directed toward a specific processing station106. In some embodiments, the single gas supply channel 932 may bepositioned to correspond to the separating station 206 of the converter100. In other embodiments, the single gas supply channel 932 may bepositioned to correspond to the piercing station 212. Alternatively, insome embodiments, the inner ring 930 may have a plurality of gas supplychannels 932 so that the gas may be introduced simultaneously to aplurality of processing stations 106, such as heating stations 202,forming stations 204, separating stations 206, piercing stations 212, orcombinations of processing stations 106.

Referring to FIG. 20, the outer ring 940 may be coupled to the mainturret 108 by one or more outer ring supports 948 so that the outer ring940 may rotate with the main turret 108 and rotate relative to the innerring 930. The outer ring 940 may have a plurality of gas deliverychannels 942 extending through the outer ring 940 from an inner surface946 to an outer surface 947 of the outer ring 940. The outer ring 940may include a plurality of connectors 923 coupled to the outer ring 940.Each of the connectors 923 may be in fluid communication with one of thegas delivery channels 942. Each of the connectors 923 may be fluidlycoupled to one of the glass tube connectors 902 (FIG. 19) through one ofthe flexible conduits 906 (FIG. 19).

Referring to FIG. 20, in operation, indexing of the main turret 108 maycause the outer ring 940 to rotate. At the end of the index time, as themain turret 108 position each of the glass tubes 102 in the nextprocessing station 106, the gas supply channel 932 of the inner ring 930may align with one of the gas delivery channels 942 of the outer ring940, thereby establishing fluid communication between the single valve908 a and the gas delivery channels 942. The valve actuator 910 may thenactuate to open the valve 908 to allow gas from the gas source 504 toflow through the gas supply conduit 922, the gas supply channel 932, andthe gas delivery channel 942, and into the distribution port 921corresponding to the processing station 106 to which it is desired todeliver the gas pulse to the glass tube 102. The gas pulse passesthrough the connector 923 and the flexible conduit 906 to the distal end152 of the glass tube 102 positioned in the processing station 106. Atthe end of the dwell time, the main turret 108 may rotate to index theglass tubes 102 to the next processing station 106. As the outer ring940 rotates with the main turret 108, the gas delivery channel 942rotates out of alignment with the gas supply channel 932 and thesubsequent gas delivery channel 942 rotates into alignment with the gassupply channel 932.

Referring to FIG. 16A, in some embodiments, the gas flow system 900 mayinclude only a single glass tube connector 902 positioned at a specificprocessing station 106, such as the separating station 206. The flexibleconduit 906 may fluidly couple the single glass tube connector 902 tothe valve 908 for controlling the flow of the gas from the gas source504 to the single glass tube connector 902. At the separating station206, the glass tube connector 902 may be inserted into the distal end152 of the glass tube 102 indexed into the separating station 206. Oncethe glass tube connector 902 is inserted, separation of the glassarticle 103 from the glass tube 102 may commence. After separation iscomplete and the meniscus 350 opened, the glass tube connector 902 maybe removed from the glass tube 102 and the glass tube 102 may be indexedto the next processing station 106. In some embodiments, the glass tubeconnector 902 may be removed from the glass tube 102 manually by anoperator of the converter 100. In other embodiments, an insertion device960 (FIG. 18) may be used to remove the glass tube connector 902 andinsert the glass tube connector 902 in the new glass tube 102. Theinsertion device may be a pneumatic, hydraulic, electromechanical, orelectromagnetic device capable of removing and inserting the glass tubeconnector 902 into the distal end 152 of the glass tube 102. Forexample, a robotic arm may be used to remove the glass tube connector902 and insert it into the glass tube 102.

Referring to FIGS. 16A-20, a method for producing an article 103 from aglass tube 102 having an inner surface may include introducing the glasstube 102 to a converter 100 having a plurality of processing stations106 comprising at least one heating station 202 and at least one formingstation 204 and heating the proximal end 150 of the glass tube 102 atthe at least one heating station 202. Alkali is released from the glasstube 102 during the heating. The method may further include forming atleast one feature of the article 103 at the proximal end 150 of theglass tube 102 in the at least one forming station 204, separating thearticle 103 from the proximal end 150 of the glass tube 102 at aseparating station 206, and introducing a flow of gas to the distal end152 of the glass tube 102 by a gas flow system 900. The gas flow system900 may include a manifold 920 fluidly couplable to the gas source 504and a plurality of glass tube connectors 902. Each glass tube connector902 may be removably coupleable to the distal end 152 of the glass tube102 and fluidly coupled to the manifold 920 by the conduit 906. For atleast one of the glass tube connectors 902, the gas flow system 900 maybe operable to pass a gas from the manifold 920, through the conduit906, through the glass tube connector 902, and into the distal end 152of the glass tube 102. Passing the gas into the distal end 152 of theglass tube 102 may produce a flow of gas adjacent to the proximal end150 of the glass tube 102. The flow of gas may be operable to remove atleast a portion of an atmosphere from an interior of the glass tube 102and reduce contamination of an inner surface 146 of the glass tube 102by alkali released from the glass tube 102.

In some embodiments, separating the article 103 from the glass tube 102may include thermal separation that produces a meniscus 350 of glassacross the proximal end 150 of the glass tube 102, and the flow of gasadjacent to the proximal end 150 of the glass tube 102 may be sufficientto open the meniscus 350. In some embodiments, introducing the flow ofgas may include introducing a gas pulse to the distal end 152 of theglass tube 102. In some embodiments, the gas pulse may have a durationless than the sum of a dwell time and an index time of the converter. Insome embodiments, the gas pulse may be sufficient to open the meniscus350 formed during thermal separation of the article 103 from the glasstube 102.

In some embodiments, the method may include introducing a plurality ofgas pulses to the distal end 152 of the glass tube 102. In someembodiments, the method may further include controlling at least one ofa duration of the gas pulse, a pressure of the gas pulse, or a volumeflow rate of the gas pulse in response to changes in a length of theglass tube 102. The flow of gas may be introduced to the distal end 152of the glass tube 102 when the glass tube 102 is positioned in one ofthe plurality of processing stations 106. In some embodiments, the flowof gas may be introduced to the distal end 152 of the glass tube 102when the glass tube 102 is positioned in the separating station 206 orthe piercing station 212 of the converter 100.

EXAMPLES

The following examples illustrate the operation of the disclosed systemand methods for reducing the SHR of glass articles manufactured fromglass tube in a converter. The following examples illustrate use of thedisclosed systems and methods for reducing SHR of glass articlesmanufactured from aluminosilicate glass tubing, such as VALOR™ glassmanufactured and marketed by Corning Incorporated. The aluminosilicateglass tubing may be further processed by annealing and/or ion exchangingthe glass tubing after converting. For some aluminosilicate glasscompositions, such as VALOR™ glass, the annealing and/or ion-exchangingprocesses subsequent to converting significantly reduce the SHR of theglass articles. The following examples illustrate the effects of thedisclosed systems and methods only on the SHR of the glass tubingresulting from the converting process and do not include the effects ofsubsequent annealing and/or ion-exchange processes. Thus, the SHR datapresented in the following examples reflects the SHR from the convertingprocess and does not represent the SHR of the final glass article. Theoperation of the disclosed systems and methods may produce differentresults for different types of glasses, such as borosilicate glasses andsoda-lime glasses, which are conventionally used to producepharmaceutical packages. The volatilization behavior of borosilicateglasses and soda-lime glasses is different than the volatilizationbehavior of aluminosilicate glasses. The SHR interactions in annealingprocesses may also be different for borosilicate glasses and soda-limeglasses compared to aluminosilicate glasses. Therefore, it should beunderstood that the SHR results produced by the disclosed systems andmethods and the process areas of the converter in which the SHRmitigation is most effective is expected to be different forborosilicate and soda-lime glass compositions compared toaluminosilicate glass compositions.

Example 1

Aluminosilicate glass tubes were converted into glass vials using aconverter. The aluminosilicate glass tubes were VALOR™ glass tubesmanufactured by Corning Incorporated. The converter used was a VialForming Machine Model RP16 with Automatic Tube Feeder manufactured byAMBEG Dr. J. Dichter GmbH, which included sixteen processing stations inthe main circuit and eight secondary processing stations in thesecondary circuit. Descriptions of the processing stations of the maincircuit of the converter used for Example 1 are provided in Table 1hereinbelow.

TABLE 1 Description of the processing stations of the converter ofExample 1 Station No. Description of Operation Type of Station A1 TubeLoading and/or Cooling Station Tube Loading/ Cooling A2 Cool an ExistingTube or Preheat a Cooling/ Newly Loaded Length of Glass Tube Heating A3Optional Separation Preheat Heating A4 Separation Preheat Heating A5Separating Separating A6 Flame Pierce of the Meniscus Piercing A7 FirstShoulder Preheat Heating A8 Second Shoulder Preheat Heating A9 ThirdShoulder Preheat Heating A10 Shoulder Forming Forming A11 FlangePreheating Heating A12 Flange Forming Forming A13 Flange FinishPreheating Heating A14 Flange Finishing Forming A15 Cooling Cooling A16Tube Drop to Determine the Vial Length Tube Drop

The converter was equipped with a gas flow system according to FIG. 5.The FIG. 5 device was configurable to allow a continuous flow of gas toall the tubes on the convertor or to cycle the gas flow on or off todeliver gas flow pulses to the glass tubes. Further, the device could beconnected to deliver gas to only one tube to test the efficacy ofdelivering gas flows at specific position(s) on the converter. It shouldbe noted that during the time when no gas flow is delivered, the end capis present, hence the top of tube is effectively closed off by thedelivery device. In this example, the convertor was setup to producevials approximately to ISO 2R using glass tube of 16.75 mm outsidediameter, 1.1 mm wall thickness, at a converter speed 31 parts perminute (ppm).

A control set of vials (Sample 1A) was produced using the converterwithout the gas flow system installed to provide a baseline comparisonto conventional processing approaches. Additional vials (Samples 1B, 1C,1D, 1E, and 1G) were produced on the converter using the gas flow systemto introduce a gas pulse at the distal end of the glass tube at selectedprocessing stations. Last, a set of vials (Sample 1F) were produced onthe converter with the gas flow system installed at the selectedprocessing stations but not utilized to deliver a gas pulse to thedistal end of the glass tube (that is the top of the tube waseffectively capped around the process). The following Table 2 provides across-reference of the sample numbers and the processing stations intowhich the gas pulse was delivered.

TABLE 2 Cross-reference of processing stations at which the gas pulsewas delivered to the glass tube in Example 1 Processing Stations IntoWhich Gas Sample No. Pulse Delivered 1A Baseline Open end configuration,FIG. 5 device not used 1B A13 only 1C A11 and A13 1D A7, A8, A9, A11,and A13 1E A5, A7, A8, A9, A11, and A13 1F None (all capped) 1G A5 only

Each of the sample vials of Example 1 were evaluated for SHR accordingto the Surface Glass Test described in USP <660>. The SHR assessmentswere performed on the sample vials, which were not annealed, but ratherwere in their as-converted state prior to any post conversionprocessing. The results of the SHR evaluation for each of the samples ofExample 1 are provided in FIG. 22 in units of milliliters of HCl per 100milliliters of analyte (ml/100 ml analyte). As shown in FIG. 22, Sample1A represents the baseline SHR of the converted glass vials manufacturedwithout introducing a gas pulse or purge at the distal end of the glasstube.

In case 1F, the gas flow system was installed but no flow was used todeliver a gas pulse to the distal end of the glass tubes during theconverting process. Instead, the gas flow system acted as a plug thatprevented the flow of gases and vapors up through the internal volume ofthe glass tube by blocking one open end of the glass tube. This approachfor case 1F provides an example similar to the conventional convertingtechnique of making the glass articles from glass tubes with one endclosed (i.e., the distal end of the glass tube is closed). As shown inFIG. 22, blocking or plugging one end of the glass tube as in Sample 1Freduced the SHR of the glass vial to about 1.5 ml/100 ml analyte. Aspreviously discussed, the highest levels of vaporized volatileconstituents are created in the hottest portion (i.e., portions of theprocess resulting in the highest glass temperatures) of the convertingprocess, which include thermal separation and piercing operations. Notintending to be bound by theory, once created, the vaporized volatileconstituents may be carried upward or downward within the internalvolume of the glass tube as the glass tube progresses through theconverting process. The direction (i.e., upward or downward) in whichthe vaporized volatile constituents are carried may be influenced byenvironmental factors, such as, but not limited to, positioning ofventing exhaust hoods; buoyancy chimney effect forces from the hot gasesrising in the glass tube; Venturi-type flows resulting from burnerheating, which induce internal flow within the glass tube; orcombinations of these. It can be appreciated that these effects can varywidely with the design and operation of a converting environment. ThisExample 1F is an illustration of the SHR implications on this glass bymitigating upward transport flow of the vaporized volatile constituentsthrough the internal volume of the glass tube by closing the distal endof the glass tube.

For Examples 1B-1D, a gas pulse is introduced to the glass tube afterthe piercing step. The glass reaches its greatest temperature in thepiercing step, which is only slightly greater than the glasstemperatures experienced during thermal separation. As previouslydiscussed, increasing the glass temperature increases the rate at whichvolatile constituents are vaporized from the glass. Thus, it isunderstood that the greatest rate of vaporization of volatileconstituents occurs during the piercing and thermal separation steps,during which the glass temperatures are the greatest. Examples 1B-1Edemonstrate the SHR impact of ejection or purging of the vaporizedvolatile constituent laden gases in the interior volume of the glasstube being processed. Comparison of Examples 1E and 1G to Example 1Fshow that delivering the gas pulse at the distal end of the glass tubeduring tube separation in the separation station A5 provides additionalreduction in the SHR of the vials compared to just capping the distalend of the glass tube as in Example 1F. The impact of gas purging theglass tube during piercing on SHR performance is shown to exceed othereffects which could be at play, such as the dynamics of piercing whichwould influence the degree and amount of volatiles which get injectedinto the tube interior at this step.

Note that for samples 1E and 1G, introducing the gas pulse at theseparating station A5 resulted in further reduction in SHR of the glassvials. One can see that SHR of approximately 1.0 was shown with purgingat separation. These examples show the beneficial effects of air pulsewhich ejects volatile laden gases generated at thermal separation andpierce. Note that in sample 1E, the piercing burner functioned as normalso that the benefit of SHR was attributable to the efficacy of thepurging pulse. This is further evidence of the benefit of purging thetube interior of volatiles

Example 1G providing interesting and unexpected results. In Example 1G,the pulse of gas flow was delivered during the entire thermal separationprocess step. It was discovered that at certain purge flows (i.e.,volume flow rate of the gas), the flow would spontaneously open themeniscus of glass remaining after separation and eliminate the need forpiercing at the next processing station Eliminating the requirement forpiercing in a vial conversion process can be of significant benefit toreducing SHR by eliminating the highest temperature area of the processand may also simplify the process and potentially enable faster partmaking speeds. This discovery enabled further research into otherapproaches to eliminate or minimize dependency on a piercing burner,covered in some of the examples below.

Example 2

For Example 2, glass vials were made using a Vial Forming Machine ModelRP18 with Automatic Tube Feeder manufactured by AMBEG Dr. J. DichterGmbH, which included eighteen processing stations in the main circuitand nine secondary processing stations in the secondary circuit. A gasflow system according to FIG. 5 was installed at the piercing station ofthe RP18 converter and configured to deliver a gas flow pulse to thedistal end of the glass tube only at the piercing station. The convertorwas setup to make approximately equivalent ISO 2R vials with 16.75 mm ODtube, 1.1 mm wall thickness, at 31 ppm conversions speed.

The gas pulse flow was increased to 2500 cubic feet per minute (cfm),which showed to be sufficient to open the molten glass meniscus formedat the proximal end of the glass tube, thus demonstrating thefeasibility of piercing the meniscus using the gas pulse, as initiallydiscovered in Example 1 previously discussed. It can be appreciated thatthe flow required to open the molten end of the tube changes dependingon the distance between the glass tube and the external injectivedevice, the specific geometry of the injector nozzle, glass temperature,meniscus thickness, and other process conditions which would be expectedto differ in converting environments.

The glass vials produced in Example 2, were evaluated for SHR accordingto the Surface Glass Test described in USP <660>. The SHR assessmentswere performed on the sample vials, which were not annealed, but ratherwere in their as-converted state prior to any post conversionprocessing. The results of the SHR for the randomly selected vials ofExample 2 are provided in FIG. 23. The SHR results in FIG. 23, whichwere obtained using externally injected air purge flow, are comparableto the SHR results for Examples 1E and 1G shown in FIG. 22, in which thegas purge was delivered in an otherwise closed end environment. Example2 is further evidence of the benefits of ejection of vaporized volatileconstituents from the internal volume of the glass tube duringconverting on the SHR of the converted glass articles. Example 2 alsodemonstrates the discovery that the air flow pulse can be used to openthe meniscus formed on the proximal end of the glass tube during thermalseparation and this can be manifested beyond a close coupled manifold ofExample 1 to a more practical externally injected manifestation.

Example 3

Example 3 illustrates the benefit of inducing purging flows by usingsuction devices to reduce SHR of the glass tube during the convertingprocess. The converter used for Example 3 was a Vial Forming MachineModel RP16 with Automatic Tube Feeder manufactured by AMBEG Dr. J.Dichter GmbH, which included sixteen processing stations in the maincircuit and eight secondary processing stations in the secondarycircuit. The converter was outfitted with a suction system having aplurality of suction tubes, similar to FIG. 12A. Each heating stationdownstream of piercing station was equipped with one of the suctiontubes. This configuration was used to demonstrate effectiveness ofinducing internal air purging by inducing downward flow by externalsuction rather than by positively introducing a flow of gas to the glasstube, as in Example 1. Referring to Table 1 hereinabove, the stationsequipped with suction tubes included stations A7, A8, A9, All, and A13.For this Example 3, alumina suction tubes were oriented below the glasstube end with the proximal end of the suction tube spaced apart from theproximal end of the glass tube by from 7 mm to 10 mm. For thisillustration, flow was regulated through a manifolded piping system to asuction pump. In this case of this experiment, it was important to limitflow levels to not overheat the experimental piping system temperaturelimits, though engineering solutions for higher temperature exhaustcould be straightforwardly manifested in a production type environment.

As with the other examples, the convertor was setup to makeapproximately equivalent ISO 2R vials with 16.75 mm OD tube, 1.1 mm wallthickness, at 31 ppm conversions speed. The sample vials for Example 3were evaluated for SHR according to the Surface Glass Test described inUSP <660>. The SHR assessments were performed on the sample vials, whichwere not annealed, but rather were in their as-converted state prior toany post conversion processing. As a baseline (i.e., sample 3A), sampleglass vials were produced from glass tube using the converter withoutapplying suction at any of the processing stations. For samples 3B, thesample vials were produced on the converter and vacuum was applied tothe proximal end of each glass tube at each of the heating stationsafter the piercing station.

FIG. 24 shows the results in SHR (ml of 0.1 molar HCl required totitrate 100 ml of solution) for samples 3A and 3B. The baseline SHRvalue of 4.44 milliliters per 100 milliliters of analyte for samples 3Amade by the conversion process with no SHR mitigation was reduced to3.12 for sample 3B by application of the suction tubes to post piercingburner locations. The SHR result achieved with application of suctiontubes therefore represents a 70% reduction in the total contribution ofall forming steps. It should be noted that baseline SHR in this case wassignificantly higher in this example than others. Not intending to bebound by theory, it is believed that higher temperature glass processconditions and unfavorable exhaust flows may have increased the baselineSHR in this Example 3. The Example 3 results illustrate the benefits toSHR performance of the glass articles resulting from purging of theglass tube interior by externally applied suction induced flows. Itshould also be noted that further experiments showed the volatile gasclouds tend to move upward through the internal volume of the glass tubemainly during the index (i.e., the time when the converter turret ismoving the glass tubes between processing stations). From example 3results, it is expected that suction approaches, such as those describedin this disclosure, would produce a purging flow effect resulting inimprovements in SHR performance similar to those demonstrated inExamples 1 and 2 for positive air flow embodiments.

While various embodiments of the converter 100 and system and methodsfor reducing the SHR of the glass tube 102 during the converting processhave been described herein, it should be understood that it iscontemplated that each of these embodiments and techniques may be usedseparately or in conjunction with one or more embodiments andtechniques.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the embodiments describedherein without departing from the spirit and scope of the claimedsubject matter. Thus it is intended that the specification cover themodifications and variations of the various embodiments described hereinprovided such modification and variations come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method for producing an article from a glasstube having an inner surface, the method comprising: introducing theglass tube to a converter having a plurality of processing stationscomprising at least one heating station, at least one forming station,and a separating station; heating a proximal end of the glass tube atthe at least one heating station, wherein alkali is released from theglass tube during the heating; forming at least one feature of thearticle at the proximal end of the glass tube in the at least oneforming station; separating the article from the proximal end of theglass tube at the separating station; and producing a flow of gasadjacent to the proximal end of the glass tube, wherein the flow of gasis operable to remove at least a portion of the atmosphere in aninterior of the glass tube.
 2. The method of claim 1, whereincontamination of the inner surface by the alkali released from the glasstube is at least reduced.
 3. The method of claim 1, wherein producingthe flow of gas adjacent to the proximal end of the glass tube comprisesproducing a flow of gas from a distal end towards the proximal end ofthe glass tube.
 4. The method of claim 1, wherein separating the articlefrom the glass tube comprises thermally separating the article from theglass tube, wherein a meniscus of glass is formed on the proximal end ofthe glass tube during thermal separation and producing the flow of gasadjacent to the proximal end the glass tube further comprises openingthe meniscus of glass.
 5. The method of claim 1, wherein producing theflow of gas adjacent to the proximal end of the glass tube comprisesproducing a positive flow of gas orthogonal to a longitudinal axis ofthe glass tube adjacent to the proximal end of the glass tube.
 6. Themethod of claim 1, wherein producing the flow of gas adjacent to theproximal end of the glass tube comprises producing a positive flow ofgas external to the glass tube and at a non-zero angle with thelongitudinal axis of the glass tube.
 7. The method of claim 1, whereinproducing the flow of gas adjacent to the proximal end of the glass tubecomprises introducing a gas pulse into the distal end of the glass tube.8. The method of claim 7, wherein separating the article from the glasstube comprises thermally separating the article from the glass tube andforming a meniscus of glass across a proximal end of the glass tube,wherein the gas pulse is sufficient to open the meniscus of the glasstube.
 9. The method of claim 7, wherein the gas pulse has a durationless than a sum of a dwell time and an index time of the converter. 10.The method of claim 7, further comprising controlling at least one of aduration of the gas pulse, a pressure of the gas pulse, or a volume flowrate of the gas pulse in response to changes in the tube diameter, wallthickness, glass type, converter operating temperatures, or combinationsof these.
 11. The method of claim 1, wherein producing the flow of gasadjacent to the proximal end of the glass tube includes producing anegative pressure at the proximal end of the glass tube.
 12. The methodof claim 1, wherein producing the flow of gas adjacent to the proximalend of the glass tube comprises producing a negative pressure pulseadjacent to the proximal end of the glass tube.
 13. The method of claim12, wherein separating the article from the glass tube comprisesthermally separating the article from the glass tube and forming ameniscus of glass across the proximal end of the glass tube, wherein thenegative pressure pulse is sufficient to open the meniscus.
 14. Themethod of claim 1, wherein producing the flow of gas adjacent to theproximal end of the glass tube comprises producing the flow of gasradially across a surface of a meniscus of glass formed on the glasstube during thermally separating the article from the glass tube,wherein the flow of gas produces a negative pressure sufficient to openthe meniscus.
 15. The method of claim 1, wherein the flow of gasadjacent to the proximal end of the glass tube is produced when theglass tube is positioned in at least one of the plurality of processingstations.
 16. The method of claim 1, further comprising indexing theglass tube between two of the plurality of processing stations, whereinthe flow of gas adjacent to the proximal end of the glass tube isproduced while indexing the glass tube between the two of the pluralityof processing stations.